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## "Mechanisms of Adult Neurogenesis in the Avian Song Circuit"

Prof. Tracy Larson , University of Virginia - Biology Department
[Host: Chris Neu]
ABSTRACT:

The Larson lab works to uncover the origin, function, and mechanisms underlying natural variation in the spatial and temporal patterns of adult neurogenesis, or birth of new neurons in the adult brain. We utilize the unique relationship between neuronal birth and death in the adult male songbird brain and the ability of the songbird to sing high quality, ‘attractive’ song to explore questions like: What are the mechanisms that promote regeneration of the adult brain? Can mechanisms that are robust in songbirds be exploited to encourage the addition of new functional neurons in the poorly regenerating mammalian brain? What cellular mechanisms modulate adult neurogenesis and how have they evolved? To accomplish our research aims, we combine several approaches including behavioral genomics, comparative neuroanatomy, cellular and molecular biology, and electrophysiology with mechanistic studies.

VIDEO:
High Energy Physics Seminar
Wednesday, November 3, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Status and Prospects for the NOvA Long Baseline Neutrino Experiment "

Erika Catano-Mur , William and Mary
[Host: Craig Group]
ABSTRACT:

Neutrino oscillations are transitions in flight between the different neutrino flavors that arise from the non-degenerate neutrino masses and lepton mixing. These transitions are evidenced in solar, atmospheric, reactor and accelerator experiments. Current experimental efforts seek to improve the precision measurements of the elements of the mixing matrix, to determine the order of the neutrino masses, and to search for evidence of neutrino/antineutrino asymmetry in oscillation probabilities.

NOvA is a long-baseline neutrino oscillation experiment, which consists of two finely segmented liquid-scintillator detectors operating 14.6 mrad off-axis from Fermilab’s NuMI muon neutrino (or antineutrino) beam. With an 810 km baseline, the measurements of muon neutrino disappearance and electron neutrino appearance allow the determination of the neutrino mass hierarchy, the octant of the largest neutrino mixing angle, and charge-parity (CP) violation in the neutrino sector. In this talk, I summarize NOvA’s most recent 3-flavor oscillation results, based on the combined analysis of neutrino and antineutrino datasets with an exposure of ~13×1020 protons-on-target in each beam mode. I also discuss the experiment’s projected sensitivities, and the potential of discovery with current and next-generation long-baseline experiments.

VIDEO:
High Energy Physics Seminar
Wednesday, October 27, 2021
4:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "The Astrophysics Program of the NOvA Experiment"

Matthew Strait , University of Minnesota
[Host: Craig Dukes]
ABSTRACT:

NOvA is a long-baseline neutrino oscillation experiment with the primary goals of discovering CP violation in the neutrino sector, determining the neutrino mass hierarchy and constraining the mixing angle theta_23. The detectors have a highly active, finely segmented design that offers superb event identification capability. Besides oscillation measurements, NOvA also has a rich cosmic ray and astrophysics program. We have set competitive limits on the flux of magnetic monopoles and for supernova-like neutrinos associated with gravitational wave events. NOvA runs its own supernova trigger and plans to participate in SNEWS. Both the Near and Far detectors are being used to search for dark matter. We have observed new details of the seasonal variation of cosmic rays at two depths and have several other cosmic rays analyses underway.

VIDEO:
High Energy Physics Seminar
Wednesday, October 6, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "High Energy Neutrino Astrophysics with Radio Techniques "

Professor Amy L. Connolly , Ohio State University
[Host: Craig Dukes]
ABSTRACT:

Multimessenger astronomy has entered an exciting new era with the recent discovery of both gravitational waves and cosmic neutrinos.  I will focus on extremely energetic neutrinos as particles that can uniquely probe the most extreme astrophysics sources at cosmic distances, as well as fundamental physics in an unexplored energy regime.  While the optical detection technique remains the most powerful for neutrino detection over a broad energy range, radio techniques have emerged in the last two decades as the most promising for a long-term program to push the neutrino frontier by over a factor of 1000 in energy.   I will present the latest results from the field of high energy neutrino astrophysics, with a focus on the balloon-borne ANITA experiment and the in-ice South Pole array ARA.  I will also give an overview of the many exciting projects in this field that are on the horizon, and their anticipated impact in terms of the astrophysics and particle physics questions that we seek to answer.

VIDEO:
High Energy Physics Seminar
Wednesday, September 29, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Track to the Future - Present and Pending Upgradings to the CMS Tracker "

Dr. Doug Berry , FNAL
[Host: Chris Neu]
ABSTRACT:

VIDEO:
High Energy Physics Seminar
Wednesday, September 22, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Unified framework for B-anomalies, muon g-2, and neutrino masses"

Anil Thapa , University of Virginia - Department of Physics
[Host: Julian Heeck]
ABSTRACT:

A model of radiative neutrino masses which also resolves anomalies reported in B-meson decays, RD(★) and RK(★), as well as in muon g −2 measurement, ∆aµ is presented. Neutrino masses arise in the model through loop diagrams involving TeV-scale leptoquark (LQ) scalars R2 and S3. Fits to neutrino oscillation parameters are obtained satisfying all flavorconstraints which also explain the anomalies in RD(★), RK(★) and ∆aµ within 1 σ. An isospin-3/2 Higgs quadruplet plays a crucial role in generating neutrino masses; we point out that the doubly-charged scalar contained therein can be produced in the decays of the S3 LQ, which enhances its reach to 1.1 (6.2) TeV at √s = 14 TeV high-luminosity LHC (√s = 100 TeV FCC-hh).

VIDEO:
High Energy Physics Seminar
Wednesday, September 15, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Precision luminosity measurement at CMS with the Pixel Luminosity Telescope "

Dr. Andres Delannoy , University of Tennessee, Knoxville
[Host: Chris Neu]
ABSTRACT:

The Pixel Luminosity Telescope is a silicon pixel detector dedicated to luminosity measurement at the CMS experiment. It consists of 48 silicon sensor planes arranged into 16 "telescopes'' such that particles originating from the CMS interaction point will pass through all three planes in the telescope. It takes advantage of the "fast-or'' readout mode built into the CMS Phase-0 pixel readout chip, which can be processed at a frequency of 40 MHz, to determine the instantaneous luminosity from the rate of triple coincidences. The full pixel information, including hit position and charge, is read out at a lower rate of ~3 kHz and can be used for studies of systematic effects in the measurement. A full rebuild of the PLT was installed in early July 2021 in anticipation of Run 3 of the LHC, which incorporates a few silicon sensors developed for the CMS Phase-2 upgrade for the High-Luminosity LHC. Several detailed studies will be presented that illustrate the impact of radiation damage on the detector performance during Run 2. The lessons learned from Run 2 and the outlook for Run 3 will be underlined. In addition, a new search for heavy-neutrinos using the vector boson fusion signature in final states with a pair of leptons and four jets will be highlighted.

VIDEO:
High Energy Physics Seminar
Wednesday, September 1, 2021
4:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "First results from the Fermilab Muon g-2 experiment"

Manolis Kargiantoulakis , Fermilab
[Host: Craig Group and Dinko Pocanic]
ABSTRACT:

The Muon g − 2 Experiment at Fermilab has measured the anomalous magnetic moment of the muon to 460 parts-per-billion, based on data collected during the first physics run in 2018. The experiment determines the anomalous precession frequency of the muon spin inside the highly uniform and precisely measured magnetic field of our storage ring. Our result is in excellent consistency with (and slightly more precise than) the BNL measurement of the same quantity from two decades ago. The combination of the experimental measurements increases the tension with the Standard Model prediction, enhancing the significance of the discrepancy to 4.2σ. In this seminar we will present the challenging experimental measurement and discuss the status of the discrepancy.

VIDEO:
High Energy Physics Seminar
Wednesday, April 28, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

Joint Nuclear/HEP seminar

## "Is double gluon bremsstrahlung in a quark-gluon plasma accurately described by the Ncolor = ∞ approximation to QCD?"

Omar Elgedawy , University of Virginia - Department of Physics
[Host: Peter Arnold]
ABSTRACT:
QCD jets produced from colliding two heavy nuclei play an important role in understanding properties of the Quark Gluon Plasma produced in these energetic collisions. During their travel through the medium, high energy partons lose their energy due to interactions with the medium through elastic collisions and medium-induced splitting processes like bremsstrahlung and pair production. In the high energy limit, these splitting processes are coherent over large distances and can no longer be treated as quantum mechanically independent, leading to a suppression of the splitting rate known as the Landau-Pomeranchuk-Migdal effect. An important question that arises is whether consecutive splittings of the high energy particle overlap within the formation time of an individual splitting. This case has been analyzed in the Nc = ∞ limit within the thick medium approximation. To see if this result applies for real QCD with Nc = 3, we calculate the next to leading order correction (i.e. O(1/N2)) to the gluon double-splitting. We have already completed a subset of the diagrams known as sequential diagrams. In this talk, I will report first results on whether the Nc = ∞  approximation to the differential rate of overlapping double bremsstrahlung of gluons is reliable, and in particular whether the correction is large or small compared to the naive expectation of 1/N2c ∼10% for Nc = 3.

VIDEO:
High Energy Physics Seminar
Wednesday, April 21, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Probing modified gravitational-wave propagation through tidal measurements of binary neutron star mergers"

Nan Jiang , University of Virginia - Department of Physics
[Host: Kent Yagi]
ABSTRACT:

Gravitational-wave sources can serve as standard sirens to probe cosmology by measuring their luminosity distance and redshift.  Such standard sirens are also useful to probe theories beyond General Relativity with a modified gravitational-wave propagation.  Most previous studies on the latter assume multi-messenger observations so that the luminosity distance can be measured with gravitational waves while the redshift is obtained by identifying sources’ host galaxies from electromagnetic counterparts.  Given that gravitational-wave events of binary neutron star coalescences with associated electromagnetic counterpart detections are expected to be rather rare,  it is important to examine the possibility of using standard sirens to probe gravity with gravitational-wave measurements alone.  In this paper, we achieve this by extracting the redshift from the tidal measurement of binary neutron stars (that was originally proposed within the context of gravitational-wave cosmology).  We also improve previous work by considering multi-band gravitational-wave observations between ground-based (e.g.  Einstein Telescope) and space-based (e.g.  DECIGO) interferometers. We find that such multi-band observations with the tidal information can constrain a parametric non-Einsteinian deviation in the luminosity distance more stringently than the case with electromagnetic counterparts (due to a larger number of available events) by a factor of a few.  We also map the above-projected constraints on the parametric deviation to those on specific theories beyond General Relativity.

VIDEO:
High Energy Physics Seminar
Wednesday, March 31, 2021
4:00 PM
Online, Room viz Zoom
Note special time.
Note special room.

## "Search for Long-Lived Particles at CMS in Runs 2 and 3 and beyond"

Ang Li , University of Virginia - Department of Physics
[Host: Chris Neu]
ABSTRACT:

Many physics beyond standard model predicts the existence of long-lived particles, which will travel a relatively long distance in the detector after it’s generation and leave some special signals in the detector such as displaced vertices, displaced jets and delayed leptons etc.. This talk introduces the search for displaced vertex, including event selection, vertex reconstruction and data-driven background estimation method. In the meanwhile, the talk also includes the structure and mechanics study for MIP Timing Detector, which is capable to measure the time information precisely when a charged particle pass through it and will be installed in CMS for high luminosity LHC era.

VIDEO:
High Energy Physics Seminar
Wednesday, March 24, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Recent Results at the NOvA Neutrino Oscillation Experiment and Developments for Future Sensitivity Improvements"

Andrew Sutton , University of Virginia - Department of Physics
[Host: Craig Group]
ABSTRACT:

NOvA is a long-baseline accelerator neutrino experiment that can probe outstanding questions in neutrino oscillation physics. Among these are: the neutrino mass hierarchy, CP violation in the lepton sector, and the determination of the neutrino mixing angle θ23. NOvA has access to these parameters by observing electron neutrino appearance and muon neutrino disappearance over an 810 km baseline. For the high statistics muon neutrino measurements the shape of the energy spectra can be used to further constrain the oscillation parameters owing to the energy dependence of neutrino oscillations. Therefore, a high resolution measurement of the neutrino energy is necessary to make precision measurements of those parameters. Moreover, uncertainties on detector calibration and neutrino interaction models have a significant impact on measurement sensitivity. NOvA has an ongoing test beam effort to improve understanding of the detector response and reduce energy calibration uncertainties. Additionally, a Long Short-Term Memory (LSTM) neural network has been developed to estimate muon neutrino and provides improved energy resolution. Interaction model uncertainties can be further addressed by adversarial network training which can be employed with different interaction generators to increase the robustness and performance of the LSTM energy estimator against model variations. This talk will present the most recent NOvA oscillation results and show ongoing work to reduce systematic uncertainties and further improve measurement sensitivity.

VIDEO:
High Energy Physics Seminar
Wednesday, March 17, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Mu2e: A New Charged Lepton Flavor Violation Experiment: Muon-Electron Conversion at Sensitivity < 10-16"

Robert Bernstein , Fermi National Lab
[Host: Craig Group]
ABSTRACT:

The Mu2e experiment will measure the charged-lepton flavor violating (CLFV) neutrino-less conversion of a negative muon into an electron in the field of a nucleus. The conversion process results in a monochromatic electron with an energy slightly below the muon rest mass. Mu2e will improve the previous measurement by four orders of magnitude using a new technique, reaching a SES (single event sensitivity) of 3 x 10^{-17} on the conversion rate, and a discovery at 2 x 10^{-16}. The experiment will reach mass scales of nearly 10^4 TeV, far beyond the direct reach of colliders. The experiment is sensitive to a wide range of new physics, complementing and extending other CLFV searches.

Mu2e is under design and construction at the Muon Campus of Fermilab with our first physics run in early 2025.

VIDEO:
High Energy Physics Seminar
Wednesday, March 3, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Reaching for the stars with CNO solar neutrinos"

Zara Bagdasarian , UC, Berkeley
[Host: Craig Dukes]
ABSTRACT:

The prime energy producer in the sun is the fusion of hydrogen to form helium. However, there is more than one way for this fusion to takeplace: for stars the size of the sun or smaller, the proton-proton (pp) chain reactions dominate (~99%), while in heavier stars, the carbon-nitrogen-oxygen (CNO) cycle is expected to play a more important role. Not only these fusion reactions would not have been possible without the emission of neutrinos, neutrinos are the only way to directly access the processes in the core of the sun.

Borexino experiment, located at the Laboratori Nazionali del Gran Sasso, was built with a primary goal of the Be7 solar neutrinos (part of pp chain) detection. In more than a decade of data taking, Borexino has not only demonstrated the unprecedentedly high sensitivity towards Be7 solar neutrinos (<3%) but performed a comprehensive study of low-energy neutrinos from the complete pp-chain. After a number of developments in both hardware and software, Borexino has presented the first experimental evidence of the up-to-now elusive CNO fusion cycle in the Sun. The absence of the CNO neutrinos signal is disfavoured by the Borexino experiment at 5σ.

VIDEO:
High Energy Physics Seminar
Wednesday, February 3, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Search for resonant decays to neutral Standard Models Bosons and MET with the CMS Detector, and the CMS Hadron Calorimeter Upgrade"

Grace Cummings , University of Virginia - Department of Physics
[Host: Bob Hirosky]
ABSTRACT:

Direct decays of proposed heavy force mediator particles to standard model leptons
have been largely excluded by past LHC searches, challenging theorists to explore more complex
decay chains. We begin our search with a framework model of a Leptophobic Z' cascading to a
pair anomalons, new Beyond the Standard Model fermions. These heavy intermediate particles decay in turn to neutral standard model bosons and a stable anomalon, which appears in the Compact Muon Solenoid (CMS) detector as missing transverse momentum (pT-miss). From a model independent point of view, this topology creates an interesting structure with a resonantly produced particle cascading to a final state with 2 missing particles, with each level of the cascade including new particles with unknown masses. To turn this into a bump hunt for the resonant particle, we employ Recursive Jigsaw Reconstruction (RJR), a rule-based methodology to systematically reduce degrees of freedom, allowing for the calculation of mass estimators at each level of our decay chain. RJR is an example of how analysis tools are evolving to be sensitive to the most well-hidden of new physics, and the detectors are doing the same. I will also give an overview of the Phase I upgrade to the CMS Hadronic Calorimeter.

VIDEO:
High Energy Physics Seminar
Wednesday, January 20, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Low-Mass Dijet Resonance Search with Calo-Scouting Techniques using CMS Run-II Data at sqrt(s)=13 TeV and, the Studies on Improvements of the CMS Detector "

Ali Eren Simsek , Cukurova University
[Host: Chris Neu]
ABSTRACT:

Physics models that allow the Standard Model to spread over a larger area often require new particles that attached to quarks and gluons and decay to dijets. The natural width of the resonances in the dijet mass spectrum (mjj) increases with coupling, and may vary from narrow resonance to wide resonance compared to experimental resolution. For example, in a model where DM (Dark Matter) particles are attached to quarks through a "DM Mediator" and the mediator can be decay to a pair of DM particles or a pair of jets and therefore can be observed as a dijet resonance. In this seminar, searches are presented for resonances with mass between 0.6 and 1.8 TeV decaying to dijet final states in proton-proton collisions at sqrt(s)=13 TeV.  The searches are performed with dijets that are reconstructed from calorimeter information in the trigger using data corresponding to an integrated luminosity of 122 /fb. The dijet mass spectrum is compared to a smooth parameterization of the QCD background and simulations of resonance signals decaying into parton pairs. Upper limits at 95% CL are presented on the production cross section of narrow quark-quark, quark-gluon and gluon-gluon resonances. This seminar also includes the studies on minor and major CMS upgrades such as HGCAL (High-Granularity Calorimeter) MIP (Minimum Ionizing Particle) Calibration Analysis with test-beam data and full ~607 meters of SPS (Super Proton Synchrotron) H2 Beamline simulation using Geant4 Beamline for 2018 HGCAL test-beam.

VIDEO:
High Energy Physics Seminar
Wednesday, January 6, 2021
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "New physics searches in ATLAS"

Boping Chen , Iowa State University
[Host: Chris Neu]
ABSTRACT:

Standard Model(SM) is a very successful theory in particle physics, which can explain most of the high energy experiment. However, still there are many open questions for the SM, such as dark matter, dark energy and gravity interaction. One of the main goal for both ATLAS and CMS detector in LHC is to search for the new physics beyond the Standard model, to give us some hint for those open questions. This talk presents two analyses for the new physics search: 1: Search for the heavy resonance Z' decaying into a Higgs boson and a photon; 2: Search for lepton flavor violation Z->emu decay. Both of these two analyses use proton proton collision data set collected by ATLAS detector from 2015 to 2018. This talk also covers some upgrade study for the ATLAS inner tracker.

VIDEO:
High Energy Physics Seminar
Wednesday, December 2, 2020
4:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Determination of the Jet Energy Scale Corrections for the Low pT Jets at root(s) = 13 TeV in CMS and Activities at HCAL Phase-1 Upgrade"

Zuhal Seyma Demiroglu , Cukurova University
[Host: Chris Neu]
ABSTRACT:

The most abundant objects produced in high-energy proton-proton collisions at the LHC are jets which are reconstructed from topologically associated energy depositions in calorimeter cells, charged-particle tracks, or simulated particles. Ideally, jets are corrected due to the intrinsic limitations of the detector system. In CMS, reconstructed jets are calibrated by using a factorized approach. This seminar will present two analyses related to jet energy scale corrections focus on the low pT region. The first part of the talk is dedicated to the Monte Carlo (MC) truth jet energy corrections for no pileup QCD PYTHIA8 sample. The study is performed using the anti-kT clustering algorithm with a distance parameter R = 0.4 in the pseudorapidity range |η| < 5.191 for jet transverse momentum 10 < pT < 905 GeV. The second part presents the calibration of the jet energy scale with respect to residual differences between data and simulation after simulation-based pre-calibrations are applied. In this analysis, low pile-up data collected by the CMS experiment in 2015 at a center-of-mass energy of 13 TeV are used. The correction factors depending on jet pT and η are derived by using two different methods based on the dijet final states in the region of |η| < 5.191 pseudorapidity and 20 < pT < 114 GeV. This will make an important contribution to the physics analysis to be performed using the low pT jets. In addition, previous physics analysis, and activities at the Phase-1 Upgrade of the CMS Hadron Calorimeter will be also presented.

VIDEO:
High Energy Physics Seminar
Monday, November 23, 2020
4:00 PM
Online, Room via Zoom
Note special date.
Note special time.
Note special room.

## "Measurement of the cross section of top quark pairs in association with a photon in lepton + jets events at root(s) = 13 TeV with CMS full Run II data"

Nabin Poudyal , Wayne State University
[Host: Chris Neu]
ABSTRACT:

The production cross-section of top quark pairs in association with a photon is measured in lepton + jets final state events during proton-proton collisions at LHC 13TeV energy using the full Run II data collected by CMS with the total integrated luminosity of  137 fb-1. The study of top quark pair production in association with a photon provides us with important information on top quark electroweak coupling. It is also sensitive to beyond the Standard Model. The analysis is done in a semi leptonic decay channel with a well isolated high Pt lepton, at least four jets from the hadronization of quarks, and an isolated photon. The photons may be emitted from initial state radiation, top quarks, and decay products of top quarks. The simultaneous maximum likelihood fitting of several control regions and kinematic observables is done extensively and carefully to distinguish the ttγ signal process from various backgrounds. The inclusive cross section of ttγ process is measured for a photon with the transverse momentum Pt ≥ 20 GeV.

VIDEO:
High Energy Physics Seminar
Wednesday, November 18, 2020
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Search for Displaced Leptons & Beam Tests for the CMS Pixel Detector Upgrade"

Bryan Cardwell , Ohio State University
[Host: Chris Neu]
ABSTRACT:

I present the two foci of my graduate research: a search for long-lived beyond-the-Standard-Model particles and R&D for the high-luminosity upgrade of the CMS pixel detector. First, I discuss the search for long-lived particles, which is performed in over 100 fb-1 of 13 TeV proton-proton collision data collected by the CMS experiment and uses electron and muon transverse impact parameter to identify displaced leptons, an exotic signature that is not covered by traditional analyses. In the second portion of the talk, I discuss the upcoming CMS silicon pixel detector upgrade, which will result in significant improvements in both functionality and radiation tolerance to stand up to the unprecedented particle flux and radiation dose of the High-Luminosity LHC. The discussion will focus on beam tests of prototype sensors and readout chips performed at the Fermilab Test Beam Facility.

VIDEO:
High Energy Physics Seminar
Wednesday, November 11, 2020
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Gravitational wave memory effects in Brans-Dicke theory"

Shammi Tahura , University of Virginia - Department of Physics
[Host: Kent Yagi]
ABSTRACT:

When gravitational waves pass through observers located far away from the source, they cause oscillatory distortions of the separations among the observers. There is one more interesting phenomenon that the gravitational waves can create lasting relative displacements of the observers, which is called the gravitational wave memory effect. Such effects are closely related to infrared properties of gravity and other massless field theories, including their asymptotic symmetries and conserved quantities. In this talk, I will present the Brans-Dicke theory in Bondi-Sachs form, discussing asymptotic symmetries, conserved charges, and the gravitational wave memory effects.

High Energy Physics Seminar
Thursday, November 5, 2020
4:00 PM
Online, Room via Zoom
Note special date.
Note special time.
Note special room.

Special HEP seminar

## "Latest Oscillation Results Combining Neutrino and Antineutrino Data from the NOvA Experiment"

Michael Baird , University of Virginia - Department of Physics
[Host: Craig Dukes]
ABSTRACT:

The NOvA experiment is a long-baseline neutrino oscillation experiment that uses the NuMI beam from Fermilab to detect both electron and muon flavored neutrinos in a Near Detector, located at Fermilab, and a Far Detector, located at Ash River, Minnesota. NOvA’s primary physics goals include precision measurements of neutrino oscillation parameters, such as θ23 and the atmospheric mass- squared splitting, along with probes of the mass hierarchy and the CP violating phase. This talk will present the latest NOvA results using a combined neutrino and anti-neutrino dataset based on a beam exposure of approximately 13 × 1020 protons-on-target in each dataset.

VIDEO:
High Energy Physics Seminar
Wednesday, November 4, 2020
3:30 PM
Online, Room via Zoom
Note special room.

## "Heavy or dark photon searches at Jefferson Lab"

Stepan Stepanyan , JLAB
[Host: Craig Dukes]
ABSTRACT:
The overwhelming evidence for dark matter (DM) in cosmological observations, manifested by its gravitational interactions, has inspired a major experimental effort to uncover its particle nature. The LHC, as well as direct and indirect detection experiments, have significantly constrained one of the best-motivated weak-scale DM models (WIMPs as dark matter candidates). In contrast, scenarios involving a light hidden sector dark matter with mediators in the MeV-GeV range has garnered a good deal of attention. Models with a hidden U(1) gauge symmetry, with a "dark" or "hidden sector" photons, are particularly attractive as they can be tested experimentally. If they exist, dark or heavy photons mix with ordinary photons through kinetic mixing, which induces their weak coupling to electrons, ∈e. Since they couple to electrons, heavy photons are radiated in electron scattering and can subsequently decay into e+e-. Experiments at Jefferson Lab use these features to search for heavy photons in the mass range of 20 MeV/c2 to 500 MeV/c2 and couplings of ∈2 > 10 -10 .
In this talk, I will summarize the experimental program for dark photon searches at Jefferson Lab. Results from the experiments that already took data, APEX and HPS, will be discussed together with plans for future measurements.

VIDEO:
High Energy Physics Seminar
Wednesday, October 28, 2020
4:00 PM
Online, Room via Zoom
Note special time.
Note special room.

## "Digital archaeology: Tomographic Imaging of the Great Pyramid of Giza"

Alan Bross , Fermilab
[Host: Craig Dukes]
ABSTRACT:

In 1970 L.  Alvarez et al. reported on the first experiment to use cosmic-ray muons to investigate the interior of a very large structure. That structure was Khafre's Pyramid at Giza.  In 2017, the Scan Pyramids team reported on the discovery of a new large void in the Great Pyramid (Khufu).  Although they used modern equipment, their system was not much larger than the one used by Alvarez's team. In order for the technique of cosmic-ray muon tomography to be able to answer detailed questions regarding the core structure of these enormous creations, a new approach must be taken.  The Exploring the Great Pyramid (EGP) Mission will use detector technology currently deployed in high-energy physics experiments to field very large muon telescopes outside of the Great Pyramid.  This will allow for a high-resolution study of almost all of its internal structure. It will go beyond simply looking for voids, but will potentially yield new information on the building techniques used to construct the Great Pyramid.  In this talk, I will review previous experiments, describe in detail the techniques the EGP Mission proposes to use and present preliminary simulation results.

VIDEO:
High Energy Physics Seminar
Wednesday, October 14, 2020
4:00 PM
via Zoom, Room Online
Note special time.
Note special room.

## "The Design, Fabrication, and Performance of a Large-Area, HighEfficiency Cosmic Ray Veto Detector for the Mu2e Experiment at Fermilab "

Steven Boi , University of Virginia - Department of Physics
[Host: Craig Dukes]
ABSTRACT:

The Muon-to-Electron-Conversion (Mu2e) Experiment is a high-precision, intensity-frontier experiment being developed at Fermilab which will search for coherent, neutrino-less muon to electron conversion in the presence of an atomic nucleus. Such a process would exhibit charged lepton flavor violation (CLFV), which has not yet been observed. Continuing the search for CLFV, Mu2e will improve the sensitivity by four orders of magnitude over the present limits. In the search for beyond the standard model (BSM) physics, Mu2e is uniquely sensitive to a wide range of models by indirectly probing mass scales up to the energy scale of 104 TeV. While muon-to-electron-conversion is permissible through neutrino oscillations in an extension of the standard model, the rate is extremely low at about one event in 1054. By design, the background for the experiment will be well-understood and kept at a sub-event level, which results in the observation of muon-to-electron conversion as direct confirmation of BSM physics. The largest background comes from processes initiated by cosmic-ray muons, which will produce approximately one CLFV-like event per day. In order to reduce this rate to less than one event over the lifetime of the experiment a large and highly efficient cosmic ray veto (CRV) detector is needed. The CRV will cover the experimental apparatus with an area of approximately 330 m2. The overall efficiency must be no les than 99.99%, a requirement that must be maintained in the presence of intense backgrounds produced by proton and muon beams. The detector employs long scintillator strips with embedded wavelength shifting fibers, read out using silicon photomultipliers. Key features of the talk involve the design, fabrication, and performance of the CRV, along with an overview of the Mu2e experiment.

High Energy Physics Seminar
Wednesday, March 4, 2020
4:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Precision timing with the CMS MIP timing detector and search for new particle production at the LHC "

Matt Joyce , University of Virginia - Department of Physics
ABSTRACT:

The Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider (LHC) is undergoing an extensive Phase II upgrade program to prepare for the challenging conditions of the High-Luminosity LHC (HL-LHC). In particular, a new timing layer will measure minimum ionizing particles (MIPs) with a time resolution of ~30ps and hermetic coverage up to a pseudo-rapidity of |η|=3. This MIP Timing Detector (MTD) will consist of a central barrel region based on LYSO:Ce crystals read out with SiPMs and two end-caps instrumented with radiation-tolerant Low Gain Avalanche Diodes. The precision time information from the MTD will reduce the effects of the high levels of pile-up expected at the HL-LHC and will bring new and unique capabilities to the CMS detector. The time information assigned to each track will enable the use of 4D reconstruction algorithms and will further discriminate interaction vertices within the same bunch crossing to recover the track purity of vertices in current LHC conditions.  We present motivations for precision timing at the HL-LHC and the ongoing MTD R&D targeting enhanced timing performance and radiation tolerance for the barrel layer components.  We will also describe the progress of our search for new physics in final states with two photons and missing transverse energy using the full Run2 dataset.

High Energy Physics Seminar
Monday, January 27, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Special Seminar

## "Light in the Dark-Opening a new window to the Dark Sector "

Ruth Pottgen , Lund University
[Host: Craig Dukes]
ABSTRACT:

The origin and observed abundance of Dark Matter in the Universe can be explained elegantly by the thermal freeze-out mechanism, leading to a preferred mass range of the Dark Matter particles in the MeV-TeV region. The GeV-TeV mass range is being explored intensely by the variety of experiments searching for Weakly Interacting Massive Particles. The sub-GeV region, however, in which the masses of most of the building blocks of stable matter lie, is hardly being tested experimentally to date.
This mass range occurs naturally in Hidden Sector Dark Matter models. The Light Dark Matter eXperiment (LDMX) is a planned electron-beam fixed-target experiment, that has unique potential to conclusively test models for such light Dark Matter in the MeV to GeV range. This presentation will give an overview of the theoretical motivation, the main experimental challenges and how they are addressed as well as projected sensitivities.

SLIDESHOW:
High Energy Physics Seminar
Thursday, November 14, 2019
4:00 PM
Physics Building, Room 204
Note special date.
Note special time.
Note special room.

Special High Energy Seminar

Slideshow (PDF)

## "Searching for Dark Matter from the Lowest to the Highest Energies "

Bjoern Penning , Brandeis University
[Host: Bob Hirosky]
ABSTRACT:

Dark Matter (DM) is a long standing puzzle in fundamental physics and goal of a diverse research program.  In underground experiments we search for DM directly using lowest possible energy thresholds, at collider we seek to produce dark matter at the very highest energies, and with telescopes we look for telltale signatures in the cosmos. All these detection methods probe different parts of the possible parameter space. I will highlight status of existing and upcoming experiments including new direct detection experiments with world leading sensitivities to start data taking in early 2020. Finally  we’ll discuss how to connect these approaches and how an interdisciplinary program bridging experimental frontiers can provide the most stringent constraints.

High Energy Physics Seminar
Wednesday, November 6, 2019
4:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "CNN Jet Image Tagging: from top measurements to new physics searches"

Dr. Kevin Nash , Rutgers University
[Host: Chris Neu]
ABSTRACT:

We detail the application of image recognition to jet tagging in CMS. The method is based on the CNN top tagging optimization seen in arXiv:1803.00107v1 and evolved to include additional color information, b tagging, and an adaptive zoom.  Additionally, we demonstrate how this jet tagging network can be decorrelated from the mass of the progenitor jet, which allows for the possibility of tagging BSM objects. We study the impact on top tagging sensitivity, the data-simulation agreement, and the versatility of the network to accept more exotic signatures.  Finally, we describe the application to the latest BSM physics searches.

High Energy Physics Seminar
Wednesday, October 30, 2019
4:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Proton Spin at Small x"

Yuri Kovchegov , Ohio State
[Host: Peter Arnold]
ABSTRACT:

An integral part of the proton spin puzzle are the contributions to the proton spin coming from quarks and gluons having very small values of the Bjorken x variable. These contributions are mostly beyond the reach of current experiments and are very hard to calculate numerically on the lattice. It appears that better theoretical understanding of quark and gluon helicity distributions at small x is needed to assess the amount of proton spin coming from this region. In my talk I will describe the recent theoretical work aimed at finding the small-x asymptotics of the quark and gluon helicity distributions, along with their orbital angular momenta (OAM). I will derive small-x evolution equation for helicity and solve them to find the small-x asymptotics of the parton helicity distributions and OAM. The results of this work can be compared to the data to be collected at the upcoming Electron-Ion Collider (EIC) and can also be used to extrapolate the small-x helicity distributions to be measured at EIC to even smaller values of x, thus constraining the proton spin coming from small x.

High Energy Physics Seminar
Wednesday, July 24, 2019
3:30 PM
Physics Building, Room 204
Note special room.

Joint Nuclear/HEP seminar

## "Light ring stability in ultra-compact objects"

Pedro Cunha , University of Lisbon
[Host: Kent Yagi]
ABSTRACT:

The following theorem is proven: axisymmetric, stationary solutions of the Einstein field equations formed from classical gravitational collapse of matter obeying the null energy condition, that are everywhere smooth and ultracompact (i.e., they have a  light ring, a.k.a. circular photon orbit) must have at least two light rings, and one of them is stable. It has been argued that stable light rings generally lead to nonlinear spacetime instabilities. Thus this result implies that smooth, physically and dynamically reasonable ultracompact objects are not viable as observational alternatives to black holes whenever these instabilities occur on astrophysically short time scales. The proof of the theorem has two parts: (i) We show that light rings always come in pairs, one being a saddle point and the other a local extremum of an effective potential. This result follows from a topological argument based on the Brouwer degree of a continuous map, with no assumptions on the spacetime dynamics, and hence it is applicable to any metric gravity theory where photons follow null geodesics. (ii) Assuming Einstein’s equations, we show that the extremum is a local minimum of the potential (i.e., a stable light ring) if the energy-momentum tensor satisfies the null energy condition.

High Energy Physics Seminar
Wednesday, April 24, 2019
3:30 PM
Physics Building, Room 204
Note special room.

## "The Exterior Spacetime of Relativistic Stars in Quadratic Gravity"

Alexander Saffer , Montana State University
[Host: Kent Yagi]
ABSTRACT:

General Relativity (GR) has been the cornerstone of gravitational physics for a century. Over this time, numerous predictions and tests have strengthened the belief in GR as the foremost theory when discussing gravity. However, GR cannot in its present form be reconciled with either quantum mechanics, or many cosmological observations such as galactic rotation curves or the accelerated expansion of the universe. In an attempt to rectify these shortcomings, modified theories of gravity have been proposed. In this talk, I will present one of these theories and discuss my work in attempting to test its validity through the development of an exterior spacetime (metric) for a neutron star. From this, we expect to be able to develop a pulse profile which can be used, in conjunction with observations made of the x-ray flux of radiating neutron stars, to place constraints on the theory.

High Energy Physics Seminar
Wednesday, April 17, 2019
3:30 PM
Physics Building, Room 204
Note special room.

## "Exploring light dark matter with the LDMX experiment"

Bertrand Echenard , Caltech
[Host: Craig Dukes]
ABSTRACT:

Understanding the nature of dark matter is a central objective of modern science, and recent theoretical developments have highlighted the importance of extending current searches over a wider range of masses. The Light Dark Matter eXperiment (LDMX) has been propose to search for light dark matter and sub-GeV New Physics in fixed-target electron-nucleus collisions with unprecedented sensitivity. The experiment is based on a missing momentum technique, in which dark matter is emitted by electrons scattering in a thin target, resulting in large missing momentum and energy in the detector. This talk will discuss the motivation for light dark matter and describe the LDMX concept and its expected performance.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 10, 2019
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Precise Measurement of the Ke2KÂµ2 Branching Ratio and New Physics Search with a Stopped K+ Beam Experiment"

Dr. Tongtong Cao , Hampton University
[Host: Craig Group]
ABSTRACT:

The J-PARC TREK/E36 experiment with a stopped K+ beam is designed to provide a more precise measurement of the branching ratio RK = Γ(K+ → e+ν)/Γ(K+ → µ+ν) than previous in-ﬂight K+ decay experiments. RK is very precisely predicted by the Standard Model (SM) with an uncertainty of 4×10−4 and any deviation from this prediction would very clearly indicate the existence of new physics beyond the SM. Additionally, the experiment is searching for dark photons/light neutral bosons (A0), which could be associated with dark matter or explain the gµ-2 anomaly and the proton radius puzzle. In the experiment, a K+ beam was stopped by a scintillating ﬁber target, and charged decay products were momentum analyzed and tracked by a 12-sector superconducting toroidal magnetic spectrometer and multi-wire proportional chambers (MWPCs) combined with a photon calorimeter with a large solid angle (75% of 4π) and 3 diﬀerent particle identiﬁcation systems. In this talk, the status of the RK and A0 analyses is presented, and the MWPC calibration and tracking by a Kalman ﬁlter are reported. This work has been supported by awards DE-SC0003884 and DE-SC0013941 in U.S., NSERC in Canada, and Kaken-hi in Japan.

High Energy Physics Seminar
Wednesday, April 3, 2019
3:30 PM
Physics Building, Room 204
Note special room.

Joint High Energy and Nuclear Seminar

## "Neutrino Physics from the PROSPECT Experiment"

Christopher White, Ph.D. , Illinois Institute of Technology
[Host: Craig Dukes]
ABSTRACT:

PROSPECT, the Precision Oscillation and Spectrum Experiment, is a reactor antineutrino experiment designed to search for eV-scale sterile neutrinos and measure the spectrum of antineutrinos from highly-enriched 235U at the High Flux Isotope Reactor (HFIR). PROSPECT uses a 4-ton, segmented 6Li-doped liquid scintillator detector to make a high-resolution measurement of the prompt energy spectrum from inverse beta decay on protons. An optical and radioactive source calibration system integrated into the active detector volume is used to characterize the optical and energy response of all detector segments. I will discuss the calibration and characterization of the PROSPECT detector and report on PROSPECT’s first measurement of the energy spectrum associated with reactor antineutrinos.

High Energy Physics Seminar
Wednesday, March 20, 2019
3:30 PM
Physics Building, Room 204
Note special room.

## "A New QCD Facility at the M2 beam line of the CERN SPS (COMPASS++/AMBER)"

Oleg Denisov , COMPASS experiment
[Host: Dustin Keller]
ABSTRACT:

Possibility to use high intensity secondary beams at the SPS M2 beam
line in combination with the world’s largest polarized target, liquid hydrogen,
liquid deuterium and various nuclear targets create a unique opportunity
for universal experimental facility to study previously unexplored aspects
of meson and nucleon structure, QCD dynamics and hadron spectroscopy.

study through Drell-Yan production of di-muon pairs. High intensity
muon beams, previously used for unique semi-inclusive and exclusive
hard scattering programs, make possible proton radius measurement in
muon-proton elastic scattering and further development of polarized
exclusive hard scattering program.

Upgrades of the M2 beam line resulting in high intensity RF-separated
anti-proton- and kaon-beams would greatly expand the horizon of experimental
possibilities at CERN: hadron spectroscopy with kaon beam, studies
of transverse momentum dependent quark structure for protons, pions and
kaons, precise studies of nuclear effects and for the first time measurements
of kaon quark—gluon substructure.

High Energy Physics Seminar
Thursday, February 28, 2019
2:00 PM
Physics Building, Room 204
Note special date.
Note special time.
Note special room.

Special Joint Nuclear and High Energy Seminar

## "TBA"

Reserved
ABSTRACT:

TBA

High Energy Physics Seminar
Tuesday, January 15, 2019
4:00 PM
Physics Building, Room 204
Note special date.
Note special time.
Note special room.

## "New results on the search for the elusive K_LâÏÎ½Î½ Ì with the KOTO detector "

Brian Beckford , University of Michigan
[Host: Craig Dukes]
ABSTRACT:

The KOTO experiment was designed to observe and study the KL→πνν decay. The Standard Model (SM) prediction for the mode is 2.4 x 10-11 with a small theoretical uncertainty [1]. An experimental upper limit of 2.6 x 10-8 was set by the KEK E391a collaboration [2]. The rare “golden” decay is ideal for probing for physics beyond the standard model. A comparison of experimentally obtained results with SM calculations permits a test of the quark flavor region and provides a means to search for new physics.

The signature of the decay is a pair of photons from the π0 decay and no other detected particles. For the measurement of the energies and positions of the photons, KOTO uses a Cesium Iodide (CSI) electromagnetic calorimeter as the main detector, and hermetic veto counters to guarantee that there are no other detected particles.

KOTO’s initial data was collected in 2013 and achieved a similar sensitivity as E391a result [3]. Since then, we completed significant hardware upgrades and had additional physics runs in 2015 at beam powers of roughly 24-40 kW. This presentation will present new results from KOTO and its search of detecting KL→πνν.

High Energy Physics Seminar
Wednesday, December 5, 2018
3:30 PM
Physics Building, Room 313
Note special room.

## "Top quark physics at the precision frontier"

Andreas Jung , Purdue
[Host: Bob Hirosky]
ABSTRACT:

The talk will highlight latest results on top quark physics at CMS employing pp collision data at a center-of-mass energy of 13 TeV. New results from other experiments and center of mass energies will also be discussed. With millions of top quarks already collected at the LHC top quark physics enters the precision era. Differential cross section measurements and top quark property measurements, in particular angular correlations, are challenging the Standard Model predictions. The intimate connection of the top quark to the Higgs Boson is scrutinized by highly precise direct measurements of the top quark mass, with alternative approaches entering the precision realm as well. The talk concludes with implications for the SM and an outlook towards the ultimate precision frontier at the high-luminosity phase of the LHC.

High Energy Physics Seminar
Wednesday, November 14, 2018
3:30 PM
Physics Building, Room 313
Note special room.

## "Frontiers in Multi-Messenger Astrophysics at the interface of Numerical Relativity and Deep Learning"

Eliu Huerta , University of Illinois, Urbana-Champaign
[Host: Kent Yagi]
ABSTRACT:

Gravitational wave observations with the LIGO and Virgo detectors from a succession of mergers of black holes are a triumph of experimental and theoretical physics, and data science.  Similarly, the observation of two colliding neutron stars in gravitational waves and light heralds the era of Multi-Messenger Astrophysics. In this talk I outline a vision to drive innovation at the interface of gravitational wave astrophysics, large scale astronomical surveys, deep learning and large scale computing to address outstanding theoretical and data science challenges to realize the full potential of Multi-Messenger Astrophysics.

High Energy Physics Seminar
Wednesday, October 10, 2018
3:30 PM
Physics Building, Room 313
Note special room.

## "Recent Results from the NOvA Neutrino Experiment"

Gavin Davies , Indiana University
[Host: Craig Group]
ABSTRACT:

Neutrinos are abundant fundamental particles throughout the universe; second-most only to the photon. They undergo a phenomenon called neutrino oscillation whereby they change flavor from one type to another as they travel. The NOvA experiment seeks to elucidate further understanding of this phenomenon utilizing Fermilab's NuMI neutrino beam and two detectors to observe neutrino interactions: a 300 ton near detector underground at Fermilab, IL and a 14 kton far detector in Ash River, MN.

The NOvA experiment has recently produced updated neutrino oscillation measurements as well as its first antineutrino oscillation results and these are presented herein.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, September 26, 2018
3:30 PM
Physics Building, Room 313
Note special room.

Slideshow (PDF)

## "Another addition to the U(1) jungle"

Triparno Bandyopadhyay , University of Calcutta
[Host: P.Q. Hung]
ABSTRACT:

In a truly model independent approach we review the class of anomaly free U(1) extensions of the SM. Parametrising the extension in terms of three observable quantities, namely, MZ′, the Z-Z′ mixing angle (alphaZ) and the extra U(1) effective gauge coupling (g'), which absorb all model dependence, we proceed to draw exclusion contours in the parameter space. For the exclusion limits we use the latest LHC DY data, unitarity, and electron--muon-neutrino scattering data. The DY data turns out to be the most stringent, but the other two constraints have situational merits, as we discuss.

High Energy Physics Seminar
Monday, August 20, 2018
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Introduction to Applied Research Institute (ARI)"

Melissa Henriksen , Applied Research Institute
[Host: Nilanga Liyanage]
High Energy Physics Seminar
Wednesday, April 18, 2018
3:30 PM
Physics Building, Room 204
Note special room.

Special Q&A Session

## "A new Signal Processing Initiative to be Based at CERN"

Sebastian N. White , CERN
[Host: Craig Dukes]
ABSTRACT:

The case for measuring the time of arrival of physics objects in the major LHC Experiments (CMS, ATLAS and TOTEM so far) has been building since it was first proposed roughly 5 years ago [?] and the LHC committee has already approved (in March 2018) for CMS to proceed to the next stage- the technical design. Along with this process there have been separately intense activities in establishing the physics performance benefits (through simulations) of this enhanced capability as well as laboratory and particle beam work to establish candidate technologies for the required level of timing precision (roughly 20-30 picosecond time resolution). A significant base for this sensor  development work has been within the “PICOSEC” collaboration, which is not part of an LHC experiment but rather evolved within 2 CERN R&D groups following a “common fund proposal” by S. White and I. Giomataris in 2014. Over the past 3 years this project has accumulated a very carefully curated data set of high quality ( 2- 5 GHz BW and 20-40 GSa/s sampling) waveforms for the principal detector technologies (Silicon with internal Gain, MicroPattern Gas structures, Micro Channel Plate PMT) and achieved world records in timing precision for all of these sensor types. We propose to build from the productive collaboration with Wolfram Research during 2017 to use this large data set to guide the design of signal processing and digitizing electronics for fast timing, which is now capturing the attention of electronics groups in the US and Europe.

High Energy Physics Seminar
Tuesday, March 20, 2018
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "An Indirect Search for Weakly Interactive Massive Particles in the Sun Using Upward-Going Muons in NOvA"

Cristiana Principato , UVA- Department of Physics
[Host: Craig Group]
ABSTRACT:

We present an indirect search for particles produced via dark matter annihilations in the Sun using a dataset collected with an upward-going muon trigger at NOvA.  Weakly Interactive Massive Particles are a theoretical non-baryonic form of Dark Matter.  The nature of Dark Matter is one of the most interesting open questions in modern physics. Evidence for DM existence comes from cosmological observations but the discovery of its particle content has not been made yet. If DM particles can produce Standard Model particles through their interactions, indirect searches like the one described here could help shed light on the dark matter mystery.

High Energy Physics Seminar
Monday, March 12, 2018
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Particle Colliders: Past, Present and Future "

Dmitri Denisov , Fermilab
[Host: Bob Hirosky]
ABSTRACT:

Developments of the particle colliders over last 50 years have seen tremendous progress in both the energy of the collisions and the intensity of the colliding beams. In order to reach even higher collision energy many fundamental inventions in the colliders design have been achieved. Progress to even higher energies was strongly stimulated by physics interests in studying smaller and smaller distances and in creation of heavier and heavier elementary particles. Experiments at colliders required major breakthroughs in the particle detection methods in order to discover new particles such as c and t quarks, gluons, tau lepton, W, Z and Higgs bosons which completed currently expected set of elementary particles. Options for even higher energy colliders will be discussed, including their design parameters, acceleration principles as well as construction challenges. Such colliders are the only way to understand Nature at even smaller distances and create particles with higher masses than we can reach today.

High Energy Physics Seminar
Wednesday, February 21, 2018
3:30 PM
Physics Building, Room 204
Note special room.

Joint HEP-Nuclear Seminar

## "Deep Learning in High Energy Physics"

Daniel Whiteson , University of California at Irvine
[Host: Chris Neu]
ABSTRACT:

Recent advances in artificial intelligence offer opportunities to disrupt the traditional techniques for data analysis in high energy physics. I will describe the new machine learning techniques, explain why they are particularly well suited for particle physics, and present selected results that demonstrate their new capabilities.

High Energy Physics Seminar
Wednesday, January 24, 2018
3:30 PM
Physics Building, Room 204
Note special room.

## "A Tale of Two Theories: Searches for Higgs Pair Production with the ATLAS Detector"

Ben Tannenwald , Ohio State University
[Host: Chris Neu]
ABSTRACT:

A new era in experimental particle physics began with the 2012 discovery of the Higgs boson by the ATLAS and CMS Collaborations. Multiple measurements have since shown the new boson possesses several properties (spin, parity, gauge couplings) consistent with the Standard Model, but many characteristics remain unknown. The nature of the Higgs self-coupling is currently unmeasured, and a precise understanding of this interaction would provide stringent new tests of the Standard Model Higgs sector. Searches for Higgs pair production have the power to confirm Standard Model predictions and help map the shape of the Higgs potential or provide a window into new physics beyond our current understanding. This seminar will summarize recent searches for Higgs pair production using the ATLAS detector. Constraints on exotic physics models will be presented and an outlook on future improvements will be discussed.

SLIDESHOW:
High Energy Physics Seminar
Monday, December 4, 2017
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Slideshow (PDF)

## "Recent Results from CUORE"

Tommy O'Donnell , Virginia Tech
[Host: Craig Group]
High Energy Physics Seminar
Tuesday, November 7, 2017
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Special Nuclear/ High Energy Seminar

## "Constraints on interacting dark matter from small scale structure"

Lan Nguyen , Notre Dame
[Host: Bob Hirosky]
ABSTRACT:

In this talk we study the effects of interacting dark matter in the structure of galactic halos. The core-cusp problem remains as one of the unresolved challenges between observation and simulations in the standard CDM model for the formation of galaxies. Basically, the problem is that CDM simulations predict that the center of galactic dark matter halos contain a steep power-law mass density profile. However, observations of dwarf galaxies in the Local Group reveal a density profile consistent with a nearly at distribution of dark matter near the center. A number of solutions to this dilemma have been proposed. We discuss the possibility that the dark matter particles themselves self interact and scatter. The scattering of dark matter particles then can smooth out their profile in high-density regions. We also summarize a theoretical model as to how self- interacting dark matter may arise. We implement this form in simulations of self-interacting dark matter in models for galaxy formation and evolution. Constraints on properties of this form of self-interacting dark matter will be summarized.

High Energy Physics Seminar
Wednesday, November 1, 2017
3:30 PM
Physics Building, Room 204
Note special room.

## "Recent results from COHERENT"

Phillip Barbeau , Duke University
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 11, 2017
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Is axion dark matter described by a classical scalar field?"

Elisa Todarello , University of Florida
[Host: Peter Arnold]
ABSTRACT:

Axion dark matter has the unique property of having extremely high quantum occupancy. This may lead to think that axion dark matter can be described in terms of a classical field.

The usual equations for the linear growth of density perturbations in the cold dark matter fluid can be obtained from the classical description of a self-gravitating scalar field in the non-relativistic regime, with differences appearing only on scales smaller than a critical length.

However, axion dark matter is expected to thermalize through gravitational self-interactions and to form a Bose-Einstein condensate. I will argue that the classical field approximation is in general not valid for thermalizing quantum fields, even in the large occupancy regime, and discuss the different evolution of a homogeneous condensate in classical and quantum field theory.

High Energy Physics Seminar
Wednesday, October 4, 2017
3:30 PM
Physics Building, Room 204
Note special room.

## "Progress on the Search for Magnetic Monopoles With the NOvA Far Detector"

Enhao Song , UVA-Department of Physics
[Host: E. Craig Dukes]
ABSTRACT:

The NOνA experiment aims to study the mixing behavior of neutrinos and will attempt to resolve the neutrino mass hierarchy. The construction and instrumentation of the 14 kT far detector finished in 2014. Due to its surface proximity, large surface area, and continuous readout, the NOνA far detector is sensitive to the detection of magnetic monopoles which would be highly ionizing particles traversing the entire detector. In order to record candidate magnetic monopole events with high efficiency and low trigger rate, we have designed a software-based trigger to make decisions based on the data recorded by the detector. The decisions must be fast, have high efficiency, and a large rejection factor for the over 100,000 cosmic rays that course through the detector every second. In this seminar, we will describe the off-beam triggering system implemented for monopole detection together with a first look at the collected data.

High Energy Physics Seminar
Wednesday, May 3, 2017
10:00 AM
Physics Building, Room 313
Note special time.
Note special room.

## "Second Numu Disappearance Results from the NOvA Experiment"

Michael Baird , UVA-Department of Physics
[Host: Craig Group]
ABSTRACT:

In light of the Nobel Prize awarded for neutrino oscillations in 2015, it is an exciting time to be a part of a long-baseline neutrino oscillation experiment. NOvA is one such experiment based out of Fermilab National Accelerator Laboratory, which uses two liquid scintillator detectors, one at Fermilab (the near" detector) and a second 14 kton detector in northern Minnesota (the far" detector.) The primary physics goals of the NOvA experiment are to measure neutrino mixing parameters through both the numu disappearance and nue appearance channels using neutrinos from the newly upgraded NuMI beam line. This talk will present a summary of the NOvA experiment and the numu disappearance results, focusing on the implications for non-maximal mixing.

High Energy Physics Seminar
Wednesday, May 3, 2017
3:30 PM
Physics Building, Room 204
Note special room.

## "Origin of Long Lifetime of Band-Edge Charge Carriers in Organic-Inorganic Lead Iodide Perovskites"

Tianran Chen , UVA- Department of Physics
[Host: Seunghun Lee]
ABSTRACT:

Long carrier lifetime is what makes hybrid organic-inorganic perovskites high performance photovoltaic materials. Several microscopic mechanisms behind the unusually long carrier lifetime have been proposed, such as formation of large polarons, Rashba effect, ferroelectric domains, and photon recycling. Here, we show that the screening of band-edge charge carriers by rotation of organic cation molecules can be a major contribution to the prolonged carrier lifetime. Our results reveal that the band-edge carrier lifetime increases when the system enters from a phase with lower rotational entropy to another phase with higher entropy. These results imply that the recombination of the photo-excited electrons and holes is suppressed by the screening, leading to the formation of polarons and thereby extending the lifetime. Thus, searching for organic-inorganic perovskites with high rotational entropy over a wide range of temperature may be a key to achieve superior solar cell performance.

High Energy Physics Seminar
Thursday, April 27, 2017
1:00 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

Condensed Matter Seminar

## "Emergent phenomena in correlated quantum materials"

Arun Paramekanti , University of Toronto
[Host: Israel Klich ]
ABSTRACT:

The interplay of quantum mechanics and many-body interactions leads to remarkable emergent phenomena in crystalline solids, ranging from intricate magnetic orders to high temperature superconductivity to electronic analogues of liquid crystals. The quest to discover, understand, and control such phases of quantum materials has led to extensive research on transition metal oxides as well as ultracold atomic gases. I will present an overview of some ongoing efforts in the field of oxide research: heavy transition metal oxides with strong spin-orbit coupling, surfaces and interfaces of complex oxides, and using strain as a knob to tune electronic properties. I will also discuss our theoretical efforts -- ranging from the study of model Hamiltonians to low energy effective theories to ongoing collaborative efforts with experimentalists -- which are aimed at understanding the rich physics of these materials.

High Energy Physics Seminar
Wednesday, April 26, 2017
3:30 PM
Physics Building, Room 204
Note special room.

Special Colloquium

## "Searching for the ttH(Hbb) and ttbb signal with novel techniques at CMS"

Marco Harrendorf , KIT
[Host: Chris Neu]
ABSTRACT:

In the last ten years we have experienced the start and the first triumphs of the Large Hadron Collider (LHC) located at CERN in Geneva, Switzerland. Surely, the discovery of a Standard Model-like Higgs boson in 2012 stands out within this context. But even though, that further major findings like Physics beyond the Standard Model eluded us so far, the quest for understanding our elementary nature is ongoing under full steam. One of the outstanding important checks is the determination if the Higgs boson is really the Higgs boson predicted by the Standard Model. An important puzzle piece in this aspect will be the discovery of the ttH signal process providing us with a direct measurement of the Top-Higgs-Yukawa coupling. The search for ttH in the bbar decay channel benefits from the large branching fraction of 58% for the Higgs to bbar decay. At the same time, the large irreducible tt+bb background poses a major challenge and requires the use of advanced analysis techniques. A further crucial ingredient is the estimation and modelling of the tt+bb background via MC event generators which is still afflicted with large theoretical uncertainties.

This talk will discuss the work on the upcoming ttH(Hbb) analysis covering the 2016 LHC data set and ongoing work to reduce the uncertainties related to the tt+bb background. Furthermore, the talk will deliver a glimpse in the future of experimental particle physics by interspersing examples of novel techniques used in the analysis, e.g. the application of Neural Networks as a classifier, Continuous integration as an improvement of the analysis workflow, and NLO event generation for obtaining more accurate simulation data.

High Energy Physics Seminar
Wednesday, April 19, 2017
3:30 PM
Physics Building, Room 204
Note special room.

## "The status of Supersymmetric Dark Matter after LHC Run I and alternatives from Grand Unification"

Keith Olive , University of Minnesota
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 29, 2017
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Status and prospective of the SoLid/CHANDLER experiment"

Camillo Mariani , Virginia Tech
[Host: Donal Day]
ABSTRACT:

The SoLid/CHANDLER experiment aims to make a measurement of very short baseline neutrino oscillations using reactor anti-neutrinos. For this purpose, a highly segmented detector was build out of PVT cubes lined with a 6LiF:ZnS(Ag)layer. Unlike neutrino experiments conducted deep underground, neutrino detectors used in a reactor environment need to operate in high levels of background radiation with very low shielding. Therefore, a reliable distinction between the neutrons produced in inverse beta decay events and signals caused by other background interaction is crucial. The composite of scintillation materials with different time constants enables the efficient use of pulse-shape analysis to discriminate against electromagnetic signals. In this talk I will present the SoLid detector, the signal identification with few example of inverse beta decays events that were collected during the first data taking of the first SoLid module and the future program that involves the use of the CHANDLER technology to increase the energy resolution of the SoLid detector.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 22, 2017
3:30 PM
Physics Building, Room 204
Note special room.

Joint Nuclear-High Energy Seminar

Slideshow (PDF)

## "Searches for New Physics Through Third Generation Particles at the ATLAS Detector "

Allison McCarn , University of Michigan
[Host: Chris Neu]
ABSTRACT:

The Standard Model (SM) has been central to particle physics for decades, and its success in predicting observational results has culminated in the 2012 discovery of a Higgs boson at the Large Hadron Collider. However, the theory is considered ‘not natural’, requiring finely-tuned parameters to allow for the precise cancellation of large radiative corrections to the Higgs boson mass. In pursuit of a more natural theory, extensions to the SM have been proposed that would stabilize the Higgs boson mass and resolve the hierarchy problem (supersymmetry, extended Higgs sectors, models with vector-like quarks).  This presentation will focus on several ATLAS searches for new physics involving third generation particles, both targeting extended Higgs sectors and vector-like quarks.

High Energy Physics Seminar
Monday, November 21, 2016
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "New Physics Searches using Jet Substructure with the CMS Experiment"

Justin Pilot , UC-Davis
[Host: Chris Neu]
ABSTRACT:

Many searches for new physics at the LHC involve decays to heavy objects such as W, Z, and Higgs bosons, or top quarks.  I will present the latest algorithms to identify hadronic decays of these objects at high momentum, where decay products may overlap in the detector.  These jet substructure algorithms aim to efficiently identify distinct topologies of particles within a jet, while simultaneously rejecting the large QCD backgrounds.  I will show the latest results from CMS searches for new physics using these signatures, including searches for top quark pair resonances and vector-like top and bottom partner quarks.  Looking toward the future, I will also discuss some new developments in the field of jet substructure being considered for new analyses.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 16, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "CERN LHC hi-lumi upgrades and Prospects for a 'Future Hadron Collider'"

Bruce P. Strauss , U.S. Department of Energy
[Host: Joe Poon]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 9, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "High-Performance Computing Resources at UVA "

Andrew Bell , ARCS
ABSTRACT:

The University of Virginia Advanced Research Computing Services (ARCS) group is committed to transforming computational research at UVA through consultation, education, and management of the University’s shared computing resources. We provide high-performance computing (HPC) expertise and service to UVA researchers from across disciplines. Our goals are to:

• Support the UVA research community's computational projects
• Advance HPC research at the University of Virginia and across the Commonwealth
• Provide computational training to a new generation of researchers
• Devise creative programming solutions on behalf of clients
• Foster a multi-disciplinary ethos
High Energy Physics Seminar
Wednesday, October 12, 2016
3:30 PM
Physics Building, Room 204
Note special room.

## "Nonextremal black holes, subtracted geometry and holography"

Mirjam Cvetic , University of Pennsylvania
[Host: Diana Vaman]
ABSTRACT:

We review the thermodynamic properties of general asymptotically flat black holes in four dimensions, suggestive of a dual conformal field theory interpretation. We introduce the so-called subtracted geometry as an asymptotically conical box'' of non-extremal black holes where the conformal symmetry becomes manifest. Employing holographic renormalization techniques in a variational problem in terms of equivalence classes of boundary data under the local asymptotic symmetries of the theory, we derive the conserved charges and the first law of thermodynamics for the subtracted geometry. We also formulate a holographic dictionary for this geometry in terms of a two-dimensional Einstein-Maxwell-Dilaton model.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 5, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Photon-photon Interaction in Rydberg Atomic Ensemble"

Bing He , University of Arkansas
[Host: Olivier Pfister and Israel Klich]
ABSTRACT:

The understanding of dynamical evolutions of interacting photon pulses in Rydberg atomic ensemble is the prerequisite for realizing quantum devices with such system. We present an approach that efficiently simulates the dynamical processes, using a set of local functions we construct to reflect the profiles of narrowband pulses. For two counter-propagating photon pulses, our approach predicts the distinct phenomena from the widely concerned Rydberg blockade to the previously less noticed significant absorption in the anomalous dispersion regime, which can occur by respectively setting the pulse frequency to the appropriate values. Our numerical simulations also demonstrate how spatially extending photon pulses become deformed under realistic non-uniform interaction over their distributions.​

High Energy Physics Seminar
Wednesday, September 7, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Atomic Seminar

## "A Search for Evidence of Supersymmetry Production at CMS "

Fan Xia , UVA - Department of Physics
ABSTRACT:

In LHC run1, the discovery of Higgs boson are striking success for the Standard Model (SM) again. Although it’s the most well-tested description of modern particle physics available today, SM is powerless in explaining hierarchy problem, dark matter in the observed universe, etc. Beyond-SM theories arise to rescue and one such theory that provides elegant solutions to many outstanding problems in SM is Supersymmetry. Based on LHC-the most powerful collider in the world, CMS experiment has achieved the chance to dig into the new particle production. This presentation will focus on one search of the susy evidence at cms, the analysis topic relies on the top pair +photons and met final state in the natural GMSB model. Currently, LHC is under the run2 data taking period at 13TeV, Run1 results and Run2 progress will be discussed.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 27, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Constraining the Standard Model with Rare Electroweak Processes: Wgg and Zgg in CMS 8TeV Data"

Alberto Belloni , University of Maryland
[Host: Bob Hirosky]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 20, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Measuring the top-Higgs coupling at CMS "

Evan Wolfe , UVA - Department of Physics
[Host: Chris Neu]
ABSTRACT:

The top-Higgs coupling is one of the remaining characteristics that has yet to be measured for the newly discovered boson. Though the standard model predicts a value for this coupling, many extensions to the standard model provide enhancements to the predicted value. While indirect measurements of the top-Higgs coupling are possible, the best approach is measuring this coupling directly at the LHC -- and the best production mechanism is through the Higgs produced in association with a top-quark pair, ttH production. This presentation will discuss the ttH results from Run I at CMS, challenges and progress of the search in Run II, and future outlook for the top-Higgs coupling measurement.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 13, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "On neutrino masses and phenomenological implications: Î¼ â e Î³ and Î¼ â e conversion"

Trinh Le , UVA- Department of Physics
ABSTRACT:

We present a model of neutrino masses in the framework of the Electroweak scale Right-handed neutrinos (EW-νR) model, which is constructed with a horizontal A4 symmetry. Such a model has several interesting phenomenological implications. We not only obtain the experimentally desired form of the PMNS matrix but also provide an explanation of why UPMNS is very different from VCKM. Moreover, the one-loop induced lepton flavor violating radiative decays li → lj  γ and μ → e conversion in an extended mirror model might be related to each other under a good approximation that we have established. Implications concerning the possible detection of mirror leptons at the LHC and the ILC as well as future searches for  μ → e conversion at Fermilab and J-PARC COMET are also discussed.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 30, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Flavor Changing Leptonic Decays of Heavy Higgs Bosons"

Marc Sher , William & Mary
[Host: Chris Neu]
ABSTRACT:

CMS has reported indications (2.4\sigma) of the decay of the Higgs boson into \mu\tau. The simplest explanation for such a decay would be a general Two Higgs Doublet Model (2HDM). In this case, one would expect the heavy neutral Higgs bosons, H and A, to also decay in a similar manner. We study two specific models. The first is the type III 2HDM, and the second is a 2HDM, originally proposed by Branco et al., in which all flavor-changing neutral processes are given by the weak mixing matrix. In the latter model, since mixing between the second and third generations in the lepton sector is large, flavor-changing interactions are large. In this model it is found that the decays of H and A to \mu\tau can be as high as 60 percent. This work has nothing to do with the 750 GeV diphoton resonance.

High Energy Physics Seminar
Wednesday, March 23, 2016
3:30 PM
Physics Building, Room 204
Note special room.

## "Rick's Story of the Underlying Event"

Rick Field , University of Florida
[Host: Craig Group]
ABSTRACT:

I will review the history of underlying event (UE) studies in hadron-hadron collisions starting with the first CDF UE analysis in 2000. Early CDF UE  measurements at 1.8 TeV and 1.96 TeV; the CDF "Tevatron Energy Scan" UE results at 300 GeV, 900 GeV, and 1.96 TeV; LHC UE studies at 900 GeV and 7 TeV: and the recent LHC UE results at 13 TeV will be examined.   I will discuss what we have learned from these studies beginning with the first CDF QCD Monte-Carlo model UE tune (Tune A), and ending with the latest CMS UE tunes (CUETP8S1, CUETP8M1, and CUETHS1).

SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 2, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Helicity Evolution at Small x"

Matthew Sievert , Stony Brook University
[Host: Simonetta Liuti]
ABSTRACT:

Almost 30 years ago, the European Muon Collaboration uncovered a crisis in nuclear physics: part of the proton's spin was missing.  The measured spin of the three valence quarks could not account for the known spin of the proton, and even today, we do not fully understand the proton's "spin budget."  This "proton spin puzzle" has driven a revolution in our understanding of the complex structure of the proton as we search for the missing angular momentum.

One possible source of angular momentum is the polarization of radiated quarks and gluons which carry a very small percentage of the proton's energy (small x) and can only be measured at particle accelerators with very high energies.  At high enough energies, multiple bremsstrahlung builds up a cascade of these small-x particles which may contain a substantial portion of the missing proton spin.

In this talk, I will describe the structure of this quantum evolution process for polarized quarks at small x.  In contrast to the more familiar cascade of unpolarized particles at small x, the polarized evolution generates double logarithms of energy and grows more quickly at high energies.  Its structure is much more complex than the unpolarized case, but early hints seem to suggest that the polarization may indeed become large at small x, making them an essential missing contribution to the proton spin puzzle.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, January 27, 2016
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Searching for Astrophysical Neutrinos with Super Kamiokande"

Erin O'Sullivan , Duke University
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, December 2, 2015
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The MINERvA neutrino experiment at Fermilab"

Jeff Nelson , College of William and Mary
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 11, 2015
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Supernova Neutrinos"

Jim Kneller , North Carolina State University
[Host: Craig Group and Bob Hirosky]
ABSTRACT:

Studying the neutrino with experiments here on Earth is a slow business. This fundamental particle is just so ephemeral under terrestrial conditions that experimenters must push the boundaries of detector technology and their patience in order to measure its properties. In contrast, a core-collapse supernovae pushes Nature's boundaries of temperature and density to the point where neutrinos become strongly coupled components of the system. In such an environment it has been shown a laundry list of neutrino properties - both Standard Model and Beyond Standard Model - alters the dynamics of the explosion. Furthermore, the neutrino signal from the next supernova in our Galaxy will also allow us to observe to the heart the explosion and extract quantitative information we can use to compare to simulations. In this talk I present some of the contributions we at NC State have made in recent years to the understanding of the  phenomenology of neutrinos in supernovae. I will pay particular attention to our recent demonstration that neutrino flavor transformation in a turbulent medium is similar to the interaction of light and matter and show how the recent generalization of the techniques we developed allow us to better understand the neutrino evolution with self-interaction as well as find uses well beyond neutrino astrophysics.

High Energy Physics Seminar
Wednesday, October 28, 2015
3:30 PM
Physics Building, Room 204
Note special room.

## "String Theory and the Real World"

Jonathan Heckman , University of North Carolina at Chapel Hill
[Host: Bob Hirosky]
ABSTRACT:

The Standard Model of particle physics provides a remarkably accurate description of Nature at small distance scales. But although this theory remains in close agreement with experiment, coupling the Standard Model to gravity leads to internal theoreticalinconsistencies at length scales much smaller than current experiments can probe. In this talk we review some of the recent progress made in formulating a self-consistent theory based on embedding the Standard Model in a strongly coupled phase of string theory known as "F-theory."  We review how this construction leads to flavor physics models in both the quark and neutrino sectors.  Time permitting, we also review recent efforts to make further contact with current and future experiments.

High Energy Physics Seminar
Wednesday, September 23, 2015
3:30 PM
Physics Building, Room 204
Note special room.

## "Status and plans of dark matter searches with LUX and LZ "

Carter Hall , University of Maryland
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, September 9, 2015
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "BSM Tensor Interaction and Hadron Phenomenology"

Simonetta Liuti , University of Virginia
[Host: Donal Day]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, May 6, 2015
3:30 PM
Physics Building, Room 204
Note special room.

Joint Nuclear/HEP Seminar

Slideshow (PDF)

## "LPM Effect in Sequential Bremsstrahlung"

Shahin Iqbal , University of Virginia
[Host: Peter Arnold]
High Energy Physics Seminar
Wednesday, April 29, 2015
3:30 PM
Physics Building, Room 204
Note special room.

## "Astroparticle physics with MeV neutrinos"

Shunsaku Horiuchi , Virginia Tech
[Host: Craig Group]
ABSTRACT:

MeV neutrinos open new strategies and challenges for a variety of topics in astroparticle physics. I will first discuss their role in understanding core-collapse supernova physics. These supernovae are among the most energetic phenomena in the Universe yet their mechanism remains unresolved. I will outline the search for the next supernova neutrinos, and describe what supernova physics can be learned from their detections. Along the way, I will demonstrate the strong interplay between supernova physics and astronomy. I will then discuss the role of neutrinos in probing the particle nature of dark matter. Dominating the matter budget of the Universe, dark matter remains one of the foremost challenges in astroparticle physics and cosmology. Neutrinos are well-positioned to becoming a new window in which to study the Universe, bringing new insights, and potentially surprises.

SLIDESHOW:
High Energy Physics Seminar
Tuesday, April 21, 2015
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Slideshow (PDF)

## "Search for disappearing tracks in proton-proton collisions at sqrt(s) = 8 TeV"

Jessica Brinson , The Ohio State University
[Host: Chris Neu]
ABSTRACT:

Many experimental searches for supersymmetry, a proposed extension to the Standard Model, have been performed at the Large Hadron Collider. Since no evidence of supersymmetry has been found, the energy scales of the theory continue to be pushed higher and higher. However, if some supersymmetric particles are long-lived they may have been missed by other conventional searches. In this talk, I will present the results of a search for long-lived supersymmetric charged particles that decay within the CMS detector and produce the experimental signature of a 'disappearing track.'

High Energy Physics Seminar
Wednesday, April 15, 2015
3:30 PM
Physics Building, Room 204
Note special room.

## "Entanglement Hamiltonians and the First Law for Entanglement Entropy"

Gabriel Wong , University of Virginia
[Host: Israel Klich & Diana Vaman]
ABSTRACT:

In the first part of this talk we will present a path integral derivation of a general relation between the ground state entanglement Hamiltonian and the physical stress tensor for a Conformal Field Theory (CFT). For spherical entangling surfaces in a CFT, this leads to first law-like relation between variations of entanglement entropy (EE) and energy as well as a set of constraint equations for the EE variation.
Via AdS/CFT, these equations can be recast as Perturbative Einstein's Equations in the bulk dual.

In the second part, we will present results on the entanglement Hamiltonian (EH) of chiral fermions living on a spatial circle. In particular we focus on the effects of periodic vs. anti periodic boundary conditions on the EH. We will relate the calculation of the fermion EH to the solution of a Riemann Hilbert Problem, and propose a generalization of Riemann Hilbert Problem for spinor bundles in higher dimensions.

High Energy Physics Seminar
Wednesday, April 8, 2015
3:30 PM
Physics Building, Room 204
Note special room.

## "An algorithmic approach to string compactification"

Lara Anderson , Virginia Tech
[Host: Peter Arnold]
ABSTRACT:

In this talk, I will outline recent progress in constructing heterotic string compactifications with realistic particle spectra and couplings in their low energy effective theories. This will involve an exploration of string "compactification" -- the process of describing very small extra spatial dimensions and how their shape and properties could effect observable physics. I will discuss new results on two long-standing challenges in string constructions.  The first is a large scale, algorithmic approach to geometrically realizing the Standard Model of particle physics in string theory.  The second is a presentation of new tools to address the problem of moduli stabilization (i.e the removal of unphysical massless particles from arising in the low energy physics of a string solution).

SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 25, 2015
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Observing Ultra-High Energy Cosmic Rays with Smartphones"

Chase Shimmin , University of California, Irvine
[Host: Chris Neu]
ABSTRACT:

In this talk I discuss the possibility of using a network smartphones and similar devices to search for ultra-high energy ($>10^{18}$ eV) cosmic rays via a community-sourced scientific platform. Muons and energetic photons produced in UHECR events leave a signature of bright pixels in images from on-board CMOS cameras, while GPS location data allows for the reconstruction of extensive air showers observed by multiple devices. The ubiquity of these consumer devices around the globe enables instrumenting a far greater area than conventional observatories, enhancing sensitivity to the very rarest events. Given certain levels of participation, it is even possible to match the observational power of state-of-the-art facilities such as the Pierre Auger observatory, at the highest energies.

SLIDESHOW:
High Energy Physics Seminar
Thursday, March 19, 2015
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Slideshow (PDF)

## "Astroparticle physics with MeV neutrinos"

Shunsaku Horiuchi , Virginia Tech
[Host: Craig Group]
ABSTRACT:

MeV neutrinos open new strategies and challenges for a variety of topics in astroparticle physics. I will first discuss their role in understanding core-collapse supernova physics. These supernovae are among the most energetic phenomena in the Universe yet their mechanism remains unresolved. I will outline the search for the next supernova neutrinos, and describe what supernova physics can be learned from their detections. Along the way, I will demonstrate the strong interplay between supernova physics and astronomy. I will then discuss the role of neutrinos in probing the particle nature of dark matter. Dominating the matter budget of the Universe, dark matter remains one of the foremost challenges in astroparticle physics and cosmology. Neutrinos are well-positioned to becoming a new window in which to study the Universe, bringing new insights, and potentially surprises.

High Energy Physics Seminar
Tuesday, February 17, 2015
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

CANCELED - RESCHEDULED FOR APRIL 21

## "Sterile neutrinos and neutrino interactions: to see or not to see, that is the question"

Mike Kordosky , College of William and Mary
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 4, 2015
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Search for new physics in multijet final states with the CMS experiment"

Tutanon Sinthuprasith , Brown University
[Host: Chris Neu]
ABSTRACT:

With the successful discovery of the standard model (SM) Higgs boson in 2012, the emphasis of the LHC physics program has shifted to understanding its properties and searching for new physics beyond the SM (BSM). Among other fascinating physics avenues at the LHC, the search for BSM physics has been the center of my interests.

The BSM physics may lie hidden in the extension of the strong sector or the uncover territory of R-parity Violating Supersymmetry (RPV SUSY). I will present the current searches for the BSM physics in multijet final states — 8 and 10 jets — predicted by three benchmark models — Coloron, Axigluon, and Gluino (RPV SUSY). The data sample, corresponding to an integrated luminosity of 19.7 fb^{-1} of proton-proton collisions at a center-of-mass energy of 8 TeV,  was collected with the CMS experiment during 2012. I will further discuss about the techniques used in the multijet background estimation. What are the weaknesses and strengths of these methods and in which direction I am pursuing the BSM physics in multijet final states at the CMS experiment.

SLIDESHOW:
High Energy Physics Seminar
Wednesday, January 28, 2015
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Mass, width, and quantum numbers: everything about the Higgs boson with 20 events"

Andrei Gritsan , Johns Hopkins University
[Host: Craig Group]
ABSTRACT:

The recently discovered Higgs boson is a completely new form of matter-energy and is believed to be a manifestation of the all-penetrating field responsible for generating mass of all elementary particles. It was observed as a resonance with mass near 125 GeV in the decay to a pair of two vector bosons on the ATLAS and CMS experiments at LHC in 2012. It is expected to have the width of about 4 MeV and the quantum numbers of the vacuum (J^PC=0^++). Yet experimental resolution allowed us to set an upper limit on the width of about 3400 MeV and only a limited number of spin-parity assignments were tested until recently. Two recent results from the CMS experiment provided a breakthrough in the study of the H boson properties: one is the measurement of the width from an interplay between the off-shell and on-shell production of the H boson, leading to a 22 MeV limit on the width, and the other is the tensor structure measurement of the H boson interactions with four pairs of vector bosons, leading to constraints on its spin-parity properties. Both results will be discussed.

High Energy Physics Seminar
Wednesday, January 14, 2015
3:30 PM
Physics Building, Room 204
Note special room.

## "Search for Third-Generation Scalar Leptoquarks and R-Parity Violating Top Squarks"

Kevin Pedro , University of Maryland
[Host: Chris Neu]
ABSTRACT:

A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.7 inverse femtobarns, collected with the CMS detector at the LHC with sqrt(s)=8 TeV. The number of observed events is found to be in agreement with the expected standard model background. Third-generation scalar leptoquarks with masses below 740 GeV are excluded at 95% confidence level, assuming a 100% branching fraction for the leptoquark decay to a tau lepton and a bottom quark. In addition, this mass limit applies directly to top squarks decaying via an R-parity violating coupling lambda'[333]. The search also considers a similar signature from top squarks undergoing a chargino-mediated decay involving the R-parity violating coupling lambda'[3jk]. Each top squark decays to a tau lepton, a bottom quark, and two light quarks. Top squarks in this model with masses below 580 GeV are excluded at 95% confidence level. The constraint on the leptoquark mass is the most stringent to date, and this is the first search for top squarks decaying via lambda'[3jk].

SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 19, 2014
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Beyond the first law of entanglement"

Misha Smolkin , University of California, Berkeley
[Host: Israel Klich]
ABSTRACT:

I will start with the first law of entanglement and its applications in QFT, then I will argue that certain calculations can be extended beyond the range of applicability of the first law and present a number of simple examples. The talk will culminate with a detailed analysis of certain open questions and related calculations.

High Energy Physics Seminar
Wednesday, November 12, 2014
3:30 PM
Physics Building, Room 204
Note special room.

## "Jet tagging with ATLAS for discoveries in Run 2"

Ayana Arce , Duke University
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 5, 2014
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "COHERENT Neutrino Physics at the Spallation Neutron Source"

Kate Scholberg , Duke University
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 29, 2014
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Novel Uses of Low-Energy Neutrino Source"

[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 1, 2014
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Quest for the nature of the neutrino"

Reyco Henning , University of North Carolina
[Host: Craig Group]
ABSTRACT:

Neutrinos are remarkable particles. They are the only known fermions that interact only via the weak force and have unusually small but finite masses. Although we have learned much about their nature over the past decades, fundamental question remain. A key one is whether neutrinos are Majorana fermions, which would imply that they are their own antiparticles. Surprisingly, this is a very difficult property to test experimentally, and the current best experimental method is to search for neutrinoless nuclear double-beta decay (NDBD). Just demonstrating the existence of this decay would show that neutrinos are Majorana fermions. In this talk I will give a theoretical and historical overview of NDBD, followed by a discussion of the experimental challenges and current international efforts to search for NDBD, with an emphasis on the Majorana experiment that is being led by UNC and Oak Ridge National Lab.

High Energy Physics Seminar
Wednesday, September 10, 2014
3:30 PM
Physics Building, Room 204
Note special room.

## "Color-Kinematic Symmetry and Gauge-Gravity Connection in the Space of Generalized Propagating Matrix and in Light-Like gauges"

York-Peng Yao , University of Michigan
[Host: Diana Vaman]
ABSTRACT:
There have been major advances in our understanding of scattering amplitudes in gauge theories and in gravity. Aside from great improvements in computational proficiency, there are hidden symmetries which connect color with kinematics. Furthermore, gauge amplitudes and gravity amplitudes are connected. We shall review these results and set up a formalism, by which such symmetries are systematically enforced and their immediate consequences become transparent. Generalized gauge freedom and interplay between color and kinematics will have a natural setting.
SLIDESHOW:
High Energy Physics Seminar
Tuesday, April 29, 2014
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Slideshow (PDF)

## "String Theory, Our Real World, and Higgs bosons"

Gordon Kane , University of Michigan
[Host: Dinko Pocanic]
ABSTRACT:
String theory is exciting because it can address most or all of the questions we hope to understand about the physical world, about the quarks and leptons that make up our world, and the forces that act on quarks and electrons to form our world, cosmology, and much more. Itâs nice that it provides a quantum theory of gravity too. Iâll explain why string theory is testable in basically the same ways as the rest of physics, why many people including string theorists are confused about that, and how string theory is already or soon being tested in several ways, including Higgs boson physics and LHC physics.
SLIDESHOW:
High Energy Physics Seminar
Friday, April 18, 2014
3:30 PM
Physics Building, Room 203
Note special date.
Note special room.

INPP Second Annual Lecture

Slideshow (PDF)

## "Extra Dimensions: Where Do We Stand?"

KC Kong , University of Kansas
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 16, 2014
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Darkness"

James D. Bjorken , SLAC
[Host: PQ Hung]
High Energy Physics Seminar
Tuesday, April 15, 2014
12:30 PM
Physics Building, Room 210
Note special date.
Note special time.
Note special room.

## "IceCube: Astrophysical neutrino measurements from the South Pole"

Mike DuVernois , Wisconsin IceCube Particle Astrophysics Center
[Host: PQ Hung]
ABSTRACT:
The IceCube detector construction completed at the end of 2010, and the full detector consisting of 5160 modules deployed in strings between 1.5 and 2.5km deep in the ice has been operating since then. I will discuss the detector, working at the South Pole, and the latest science results from IceCube which include the first detections of high-energy astrophysical neutrinos. Other recent work has looked at gamma-ray burst neutrinos (and placed an interesting limit), the cosmic-ray anisotropy, and indirect searches for Dark Matter.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 9, 2014
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Is the size of Θ13 related to the smallness of the solar mass splitting?"

Amitava Raychaudhuri , Calcutta University
[Host: PQ Hung]
ABSTRACT:
Θ13 is small compared to the other neutrino mixing angles. The solar mass splitting is about two orders smaller than the atmospheric splitting. We indicate how both could arise from a perturbation of a more symmetric structure. The perturbation also affects the solar mixing angle and can tweak alternate mixing patterns such as tribimaximal, bimaximal, or other variants to viability. For real perturbations only normal mass ordering with the lightest neutrino mass less than 10-2 eV can accomplish this goal. Both mass orderings can be accommodated by going over to complex perturbations if the lightest neutrino is heavier. The CP-phase in the lepton sector, fixed by Θ13 and the lightest neutrino mass, distinguishes different options.
High Energy Physics Seminar
Tuesday, April 8, 2014
2:00 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

## "Evidence for s-channel single top production at CDF"

Hao Liu , University of Virginia
[Host: Craig Group]
High Energy Physics Seminar
Wednesday, January 15, 2014
3:30 PM
Physics Building, Room 204
Note special room.

## "First Dark Matter Search Results from the LUX Detector"

Karen Gibson , Case Western Reserve University
[Host: Chris Neu]
ABSTRACT:
I will present the results from 85 days of data collected by the LUX experiment. The LUX detector is a two-phase xenon time-projection chamber designed to search for the scattering of WIMP dark matter in liquid xenon. LUX has been operating underground at the 4850' level of the Sanford Underground Research Facility in Lead, SD, since February 2013, and WIMP search data was collected between April and August 2013. I will review the unblinded analysis of our initial dataset and discuss the results from our search, which provides world-leading sensitivity to WIMP dark matter.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 13, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Non-Constant Dark Energy Models and the Possible Fates of the Universe"

Kevin Ludwick , University of Virginia
[Host: PQ Hung]
ABSTRACT:
Dark energy, responsible for the apparent acceleration of the Universe, is typically considered to be represented by a cosmological constant. However, according to the latest results from WMAP 9 and Planck, the measured 2-sigma range for the equation-of-state parameter lies below -1, which is indicative of a dark energy density that increases over time, i.e., phantom dark energy. I discuss the full categorization of dark energy models with monotonically increasing dark energy densities, introducing two new categories described by what we have dubbed the "little rip" and the "pseudo-rip." I present example parameterizations for each type and discuss the implications for bound structures and the Universe itself in the future.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 6, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Neutrino Advances and Developments in Finite Group Models"

David Eby , Vanderbilt University
[Host: Kevin Ludwick]
ABSTRACT:
Neutrino discoveries over the last decade and a half have provided the first definite observation of particle physics beyond the standard model. The ramifications of these results are continuing to impact the theory community, as its members struggle to adapt old models and develop new ones. Finite group models have been particularly successful at providing explanations for new neutrino behavior. Our work, titled Binary Tetrahedral Flavor Symmetry or the Tâ Model, endeavors to bridge the quark and lepton families in a single coherent system by means of additional Higgs-like particles. This theory provides testable predictions for neutrino mixing, quark mixing, and dark matter. Where possible, we evaluate these predictions against current experimental evidence and find agreement with the atmospheric and reactor neutrino mixing angles, an accurate prediction of the Cabibbo angle, and a dark matter candidate outside of current limits. Taken together, we believe these results speak to the promise of finite groups and flavor symmetries to accurately approximate nature.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 30, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The Higgs Boson in the Golden Channel"

Jamie Gainer , University of Florida
[Host: Craig Group]
ABSTRACT:
The "Golden Channel", in which the Higgs decays to four leptons via intermediate Z bosons, has played an important role in the discovery of the Higgs and in early measurements of its properties. I review the discovery of the Higgs in this channel and describe ongoing efforts to use this channel to measure Higgs couplings to Z bosons.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 23, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Recent results from the KLOE/KLOE-2 experiment"

Anthony Palladino , INFN Frascati, Italy
[Host: Dinko Pocanic]
ABSTRACT:
Analysis of KLOE data collected during the period 2001-2005 (integrated luminosity ∼2 fb−1 continues to provide interesting physics results. A recently published upper limit on the branching ratio of the pure CP violating process BR(KS → 3π0) < 2.6 Ã 10−8 is an order of magnitude larger than predictions based on the Standard Model. A search for CPT and Lorentz symmetry violation with φ → KS KL → π+ππ+π has allowed an independent measurement of all four CPT violating parameters, Δaμ, appearing for neutral kaons in the Standard-Model Extension framework. The measurement of the e+e → π+π(γ) cross section below 1 GeV provides important limits on the hadronic contribution to the Standard Model calculation of the g−2 of the muon, where a long standing 3σ discrepancy is observed. Additionally, KLOE is searching for a dark U boson in the processes φ → η e+e and e+e → μ+μγ. The KLOE-2 experiment is ready to begin taking data this fall.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 16, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Joint HEP-Nuclear Seminar

Slideshow (PDF)

## "Improving Weak Boson Fusion (WBF) LHC Higgs analyses with Fox-Wolfram Moments"

Catherine Bernaciak , University of Heidelberg
[Host: Craig Group]
ABSTRACT:
In this talk i will present a technique for improving Higgs analyses involving WBF at the LHC. It is common nowadays to use multivariate techniques to construct classification rules with which to separate signal from background events. This is a vital aspect of many LHC analyses. The choice of variables used to train the classification rule has so far been rather straightforward, i.e. distributions in the rapidity, transverse momentum, and invariant mass of the leading jets. In this talk I will show that by incorporating Fox Wolfram moments - variables that describe different types of correlations between jets - into the multivariate analyses there is a significant improvement in the ability to discern a Higgs boson signal produced via WBF from background processes. As examples I will consider the Higgs diphoton and Higgs tau tau channels.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 2, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The latest evidence for s-channel single top production"

Aran Garcia-Bellido , University of Rochester
[Host: Bob Hirosky]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, September 25, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Probing New Physics with ORKA"

Elizabeth Worcester , Brookhaven National Lab
[Host: Craig Group]
ABSTRACT:
ORKA is a proposed experiment to measure the K+ -> pi+ nu nubar branching ratio with 5% precision using the Fermilab Main Injector high intensity proton source. The detector design is based on the BNL E787/E949 experiments, which observed seven candidate events. Two orders of magnitude improvement in sensitivity relative to the BNL experiments comes from enhancements to the beam line and the detector acceptance. Precise measurement of the K+ -> pi+ nu nubar branching ratio with the same level of uncertainty as the well-understood Standard Model prediction allows for sensitivity to new physics at and beyond the LHC mass scale. I will describe the motivation for, design of, and status of the ORKA experiment.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, September 18, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Polaroid jetography: an album of jet physics measurements and searches at the ATLAS experiment"

Caterina Doglioni , University of Geneva
[Host: Bob Hirosky]
ABSTRACT:
In Quantum ChromoDynamics (QCD), confined quarks and gluons from the proton-proton scattering manifest themselves as groups of collimated particles in the final state. These particles are clustered into physically measurable objects called hadronic jets. Jets are widely produced at hadron colliders: they are the key physics objects for a rediscovery of QCD and for searches for New Physics. This talk presents a series of snapshots from the extensive album of the ATLAS jet physics program with the Large Hadron Collider 7 and 8 TeV dataset, starting from an overview of jet reconstruction and calibration techniques and outlining a selection of measurements and searches with jets.
SLIDESHOW:
High Energy Physics Seminar
Tuesday, September 17, 2013
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Slideshow (PDF)

## "Long-baseline neutrino experiments with the NuMI beam"

Patricia Vahle , College of William and Mary
[Host: R. Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, August 28, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Seach for Standard Model Higgs in t‾tH, H→ bÂ¯b decay channel at √ s = 8 TeV"

John Wood , University of Virginia
[Host: Chris Neu]
ABSTRACT:
The most important goal of the Large Hadron Collider (LHC) is to elucidate the mechanism of electroweak symmetry breaking. The Standard Model(SM) Higgs Boson is thought to be a prime candidate for this. Recent observations of a new boson with mass of 125GeV are consistent with a SM Higgs, however the properties of this new particle must now be understood in order to say anything conclusive about its relationship to a SM Higgs. The observation of this new particle in association with top quarks would allow the couplings of this particle to top and bottom quarks to be measured. tÂ¯tHiggs, Higgs to bÂ¯b is an excellent branch to explore due to the dominant branching ratio of Higgs to bÂ¯b and the kinematic handle the tÂ¯t offers on the event. However, it presents some difficult challenges due to a low signal to background ratio and uncertainties of SM backgrounds. This talk describes a search for the SM Higgs boson in association with top quarks, using Monte Carlo (MC) simulations. MC to Data comparisons are made with pp collisions collected by the CMS detector.
High Energy Physics Seminar
Wednesday, April 24, 2013
3:30 PM
Physics Building, Room 204
Note special room.

## "Anomalies in the Forward-Backward Asymmetry of Top Quark Pair Production at the Tevatron"

Jon Wilson , University of Michigan
[Host: Craig Group]
ABSTRACT:
Top quark pairs at the Tevatron are produced with an anomalously large forward-backward asymmetry. Discovering the source of this asymmetry is a major physics goal for analyses at the Tevatron and the LHC, because it is difficult to account for within the Standard Model, and may point the way towards new physics. We find that this asymmetry depends approximately linearly on the top quark pair mass and on the rapidity difference between the top and anti-top. We also observe an asymmetry when studying only the lepton in semi-leptonic top pair events which is consistent with the top pair asymmetry. Finally, we see an anomalously large linear term in the top quark pair differential cross section, which is sufficient to account for the asymmetry. These results may be indicative of undiscovered phenomena, or they may spur advances in Standard Model computations.
High Energy Physics Seminar
Wednesday, April 17, 2013
3:30 PM
Physics Building, Room 204
Note special room.

## "A Search for Gauge Mediated Supersymmetry Breaking at the Compact Muon Solenoid in Events with Two Photons, Third Generation Quarks, and Large Missing Energy"

Brian Francis , University of Virginia
High Energy Physics Seminar
Wednesday, April 3, 2013
3:30 PM
Physics Building, Room 204
Note special room.

## "Electromagnetic properties of neutrinos"

Jarek Novak , University of Minnesota
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 27, 2013
12:00 PM
Physics Building, Room 313
Note special time.
Note special room.

Special Seminar -- pizza will be served

Slideshow (PDF)

## "Search of Magnetic Monopoles with the NOvA Detector"

Zukai Wang , University of Virginia
[Host: Craig Dukes]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 20, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Electromagnetic properties of neutrinos"

Jarek Nowak , University of Minnesota
[Host: Craig Group]
High Energy Physics Seminar
Wednesday, March 6, 2013
3:30 PM
Physics Building, Room 204
Note special room.

## "Electroweak-scale Right-handed Neutrino Model and 126 GeV Higgs-like Particle"

Ajinkya Kamat , University of Virginia
[Host: PQ Hung]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 27, 2013
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Electroweak-scale Right-handed Neutrino Model Contribution to Oblique Parameters"

Vinh Hoang , University of Virginia
[Host: PQ Hung]
High Energy Physics Seminar
Wednesday, February 13, 2013
3:30 PM
Physics Building, Room 204
Note special room.

## "How to understand superfluids using field theory"

Mark Alford , Washington University in St. Louis
[Host: Diana Vaman]
ABSTRACT:
The hydrodynamic description of a superfluid at non-zero temperature is the two-fluid model, where the two fluids are the superfluid and a normal fluid. The superfluid is a Bose-Einstein condensate, and the normal fluid is a thermal gas of phonons.

I will show how one can translate between the macroscopic two-fluid model and a microscopic field theoretic description, using the simplest field theory that can show Bose-Einstein condensation, namely the complex scalar field.

Questions that will be answered include:
* How can one get two fluids from a single field?
* What is the relationship between the different formalisms that have been proposed for relativistic superfluids?
* What is the role of the Goldstone boson?
High Energy Physics Seminar
Wednesday, January 30, 2013
3:30 PM
Physics Building, Room 204
Note special room.

## "Indirect Searches for Dark Matter with the Fermi Large Area Telescope"

Andrea Albert , Ohio State University
[Host: Chris Neu]
ABSTRACT:
There is overwhelming evidence that non-baryonic dark matter constitutes ~23% of the energy density of the universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce gamma rays via annihilation or decay detectable by the Fermi Large Area Telescope (Fermi LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. I will present recent results from indirect WIMP searches by the Fermi LAT Collaboration. I will focus on our recent search for gamma-ray spectral lines from WIMP annihilations with 4 years of data. There has been recent excitement with the report of a line-like feature localized in the galactic center around 130 GeV. I will be discussing what our search finds and the systematic checks we've performed on potential signals.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, December 5, 2012
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Continuity of the Deconfinement Transition in (Super) Yang Mills Theory"

Thomas Schaefer , North Carolina State University
[Host: Diana Vaman]
ABSTRACT:
Finding controlled, analytical approaches to the deconfinement transition in QCD is an old problem. Here we present a weak coupling calculation of the deconfinement transition in a deformed version of QCD. We argue that this transition is continuously connected to the transition in pure gauge theory, which takes place in strong coupling.

More technical abstract: We study the phase diagram of SU(2) Yang-Mills theory with one adjoint Weyl fermion on R^3xS^1 as a function of the fermion mass m and the compactification scale beta. This theory reduces to thermal pure gauge theory as m->infinity and to circle-compactified (twisted) susy gluodynamics in the limit m->0. In the m-L plane, there is a line of center symmetry changing phase transitions. In the limit m->infinity, this transition takes place at beta_c=1/T_c, where T_c is the critical temperature of the deconfinement transition in pure Yang-Mills theory. We show that near m=0, the critical scale beta_c can be computed using semi-classical methods and that the transition is of second order. This suggests that the deconfining phase transition in pure Yang-Mills theory is continuously connected to a phase transition that can be studied in weak coupling. The center symmetry changing phase transition arises from the competition of fractionally charged instanton-monopoles and instanton molecules. The calculation can be extended to higher rank gauge groups and non-zero theta angle.

SLIDESHOW:
High Energy Physics Seminar
Thursday, November 15, 2012
2:30 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

Slideshow (PDF)

## "New technique(s) for mass measurement at hadron colliders"

Kaustubh Agashe , University of Maryland
[Host: Diana Vaman]
ABSTRACT:
I will first analytically show a simple, yet subtle "invariance" of two-body decay kinematics for the case of a massless daughter and a mother particle which is unpolarized and has a generic boost distribution in the laboratory frame. Namely, the laboratory frame energy distribution of the massless decay product has a peak, whose location is identical to the (fixed) energy of that particle in the rest frame of the corresponding mother particle. As a proof of principle of the usefulness of this observation, I will then apply it for measuring the mass of the top quark at the LHC, using simulated data and including experimental effects. Finally, I will show how it can be used to measure all the superpartner masses in a cascade decay chain of the gluino.
High Energy Physics Seminar
Wednesday, November 7, 2012
3:30 PM
Physics Building, Room 204
Note special room.

## "Status and Outlook for the NOvA Experiment"

Martin Frank , Fermilab
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 24, 2012
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Flavor Violation and theta(13) in the A4 Randall-Sundrum Model"

Avihai Kadosh , University of Groningen
[Host: Israel Klich]
ABSTRACT:
I will discuss the A4 Randall-Sundrum model, aimed at a simultaneous explanation of quark and lepton masses and mixings. After introducing the model setup, I discuss the LO and NLO results for fermion masses and the quark and neutrino mixing.

In particular, I will demonstrate the way realistic CKM and PMNS matrices can be accommodated with natural O(1) parameters, considering also the recent measurements of theta(13) by RENO and DAYA Bay. I then discuss the phenomenology of RS-A4 and the most significant constraints coming from EWPM and rare processes in both the quark and lepton sectors. Special attention will be given to the calculation of 1-loop contributions to dipole operators relevant for the nEDM.

Finally, I discuss Tree level contributions to cLFV (mu-->e,3e) and B_{s,d}-->mu+mu- mediated by anomalous Z couplings, in light of the wealth of current day and future experiments addressing these processes. It is shown that cLFV together with EWPM, impose the strongest constraints on the Kaluza-Klein scale and the model parameters.

High Energy Physics Seminar
Wednesday, October 17, 2012
3:30 PM
Physics Building, Room 204
Note special room.

## "Looking for Light at the End of the LHC Tunnel: The Search for SUSY with Photons at CMS"

David Mason , Fermi National Accelerator Laboratory
ABSTRACT:
After the expectation exceeding 7 TeV run in 2011, CMS quickly excluded much of the phase space where early SUSY was proposed to be lurking. In 2012, with the LHC producing collisions at unprecedented rates at 8 TeV, we are transitioning from "simple" cut & count searches for early new physics to more subtle and challenging signatures. Those with photons in the final state form one of the cornerstones of the 2012 CMS SUSY search strategy. Photons can be identified with high purity in CMS and are predicted to be harbingers of new physics, from Gauge Mediated SUSY to Universal Extra Dimensions. Here I will present CMS's most recent SUSY search results, emphasizing those utilizing photon signatures.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, September 12, 2012
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Search for the Higgs at the LHC in the Channel H->WW->lvjj"

Joey Goodell , University of Virginia
[Host: Chris Neu]
ABSTRACT:
A search for the Higgs boson of the Standard Model through the H->WW->lvjj decay channel from p-p collisions at sqrt(7) TeV will be described. The data were collected with the CMS detector at the LHC in 2011 in a data sample corresponding to an integrated luminosity totaling 4.6 fb^-1. Two simple techniques have been studied so far; the expected limit as a function of the Higgs mass in the range 250-600 GeV will be compared to the reference results of CMS from the 2011 data sample. Further, I will describe data-driven background models for W+jets and QCD multijet production and a multivariate Higgs signal extraction technique we are developing; these will be deployed in the 2012 search in this channel. I will conclude by talking about the future of the CMS physics program in the High-Luminosity LHC era, including preliminary tests of a new radiation-hard GaAs avalanche photo-detector.
High Energy Physics Seminar
Tuesday, May 1, 2012
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Explaining the Tevatron ttbar asymmetry with light axigluons"

Christian Spethmann , Boston University
[Host: PQ Hung]
ABSTRACT:
The forward-backward asymmetry of ttbar pair production at the Tevatron remains the most startling potential signal of new physics to date. In this talk I review a range of models that have been introduced to explain the anomaly and discuss experimental constraints on those new physics models. I then explore the feasibility of explaining the ttbar asymmetry with a light axigluon, and discuss search strategies for such an axigluon at the LHC.
High Energy Physics Seminar
Wednesday, April 25, 2012
12:00 PM
Physics Building, Room 313
Note special time.
Note special room.

## "The Spin of Holographic Electrons at Nonzero Density and Temperature"

Chris Herzog , Princeton University
[Host: Diana Vaman]
ABSTRACT:
I will provide some general motivation for using gauge string duality (AdS/CFT) to study the physics of quantum phase transitions and strange metals. Then I will describe some recent work investigating the role of spin in holographic models of Fermi and non Fermi liquids. In particular, I will show the mark spin-orbit coupling leaves on the dispersion relation. Additionally, I will show how spin affects relaxation times.
High Energy Physics Seminar
Wednesday, April 25, 2012
3:30 PM
Physics Building, Room 204
Note special room.

## "The Energy Dependence of the Underlying Event"

Rick Field , University of Florida
[Host: Craig Group]
High Energy Physics Seminar
Tuesday, April 10, 2012
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Measurement of CP Violation in Bs to J/Psi Phi Decays at CDF"

Gavril Giurgiu , Johns Hopkins University
ABSTRACT:
We present a measurement of the CP-violating parameter beta_s using approximately 6500 Bs to J/Psi Phi decays reconstructed with the CDFII detector in a sample corresponding to 5.2/fb of integrated luminosity. We find the CP-violating phase to be within the range [0.02, 0.52] U [1.08, 1.55]\$ at 68% We consider the inclusion of a potential S-wave contribution to the Bs to J/psi K+K- final state which is found to be negligible over the KK mass interval considered. We also present measurements of the Bs decay width difference and mean lifetime as well as the final state polarization fractions.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 4, 2012
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Virginia and Maryland String and Particle Theory Meeting"

Balasubramanian, Cvetic, Kharzeev, & Langacker , University of Pennsylvania, Brookhaven National Laboratory, & Institute for Advanced Study
[Host: Diana Vaman]
ABSTRACT:
10-11 a.m. - Dmitri Kharzeev (Brookhaven National Laboratory)
"The chiral magnetic effect and chiral hydrodynamics of relativistic plasmas"

The interplay of quantum anomalies, topology and magnetic field results in a number of surprising phenomena in relativistic plasmas. In particular, the chirality imbalance induces the separation of electric charge along the axis of magnetic field (the Chiral Magnetic Effect, CME). The existence of CME has been confirmed by the lattice QCDxQED computations, and there is an evidence for it from heavy ion experiments at RHIC and LHC. The CME current is non-dissipative, and persists in strongly coupled systems that admit hydrodynamical description. Quantum anomalies significantly affect the hydrodynamics of relativistic plasmas leading in particular to the emergence of novel gapless collective excitations. Apart from the quark-gluon plasma, the CME current and related phenomena can exist in chiral materials (e.g. graphene, topological insulators, and Weyl semi-metals).

11 a.m.-12 p.m. - Mirjam Cvetic (University of Pennsylvania)
"General Black Holes and Their Microscopics"

We review properties of multi-charged rotating black holes in asymptotically Minkowski and anti-deSitter space-times, as solutions of maximally supersymmetric compactifications of String Theory. We focus on recent progress in deriving the conformal invariance and the microscopics of general, asymptotically flat rotating black holes in four- and five-dimensions.

2-3 p.m. - Vijay Balasubramanian (University of Pennsylvania)
"Momentum space entanglement and renormalization in quantum field theory"
The degrees of freedom of any interacting quantum field theory are entangled in momentum space. Thus, in the vacuum state, the infrared degrees of freedom are described by a density matrix with an entanglement entropy. We derive a relation between this density matrix and a Wilsonian effective action. We argue that the entanglement entropy of and mutual information between subsets of field theoretic degrees of freedom at different momentum scales are natural observables in quantum field theory and demonstrate how to compute these in perturbation theory. The results may be understood heuristically based on the scale-dependence of the coupling strength and number of degrees of freedom. We measure the rate at which entanglement between degrees of freedom declines as their scales separate and suggest that this decay is related to the property of decoupling in quantum field theory.

3-4 p.m. - Paul Langacker (Institute for Advanced Study)
"New Physics from the String Vacuum"

Concrete semi-realistic string constructions often lead to predictions for low energy physics that are more complicated than the usual MSSM paradigm. These often include string remnants such as additional U(1)' gauge symmetries, extended quasi-chiral fermion sectors, and extended Higgs/neutralino sectors. Non-standard mechanisms for obtaining small Dirac or Majorana neutrino masses (or both) are another common occurence. Examples of such beyond the MSSM'' physics and their consequences will be discussed, mainly drawn from Type IIA quivers.

High Energy Physics Seminar
Saturday, March 31, 2012
10:00 AM
Physics Building, Room 204
Note special date.
Note special time.
Note special room.

Virginia and Maryland String and Particle Theory Meeting

## "The New Muon g-2 Experiment at Fermilab"

Mandy Rominsky , Fermi National Accelerator Laboratory
[Host: Bob Hirosky]
ABSTRACT:
The measurement of the anomalous magnetic moment of the muon provides a test of the standard model and a handle on physics beyond the standard model. A new experiment at Fermilab has been proposed to resolve the current discrepancy of 3 sigma between theory and experiment. The principles, history and current experimental proposal will be discussed in this talk.
High Energy Physics Seminar
Wednesday, March 14, 2012
3:30 PM
Physics Building, Room 204
Note special room.

## "T-odd Transverse Momentum Distributions and Role of the Strong Coupling Constant"

Aurore Courtoy , IFPA University of Liege
[Host: Simonetta Liuti]
High Energy Physics Seminar
Tuesday, March 6, 2012
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Holographic Quantum Quench"

Sumit Das , University of Kentucky
[Host: Diana Vaman]
ABSTRACT:
The holographic correspondence between non-gravitational field theories and gravitational theories in one higher dimension can be used to study non-equilibrium behavior of strongly coupled quantum field theories. One such phenomenon is that of quantum quench, where a coupling of the field theory is time dependent and typically asymptotes to constants at early and late times. In the gravity dual this can describe, under suitable circumstances, either black hole formation, or passage through a spacelike region of high curvature similar to a cosmological singularity. In particular in recent work holography has been used to study situations where quantum quench happens across a critical point, and has revealed interesting scaling properties.
High Energy Physics Seminar
Wednesday, February 29, 2012
3:30 PM
Physics Building, Room 204
Note special room.

## "Is the universe as we know it unstable?: What a Higgs mass ~ 125 GeV would mean for the Minimal Standard Model"

Peter Arnold , University of Virginia
[Host: Craig Dukes]
ABSTRACT:
This will be an informal talk explaining an old story about vacuum instability for light enough Higgs bosons. If the Minimal Standard Model (meaning no new physics other than a single Higgs boson) is a good description of nature up to very large energy scales, then a Higgs mass less than somewhere around 130 GeV would mean that the current "vacuum" of the Universe is a meta-stable state that will someday decay, with disastrous consequences for the physical world as we know it. The original framework of this story featured UVa's own PQ Hung in 1979, and its later development included some work by the speaker himself a score of years ago.
High Energy Physics Seminar
Wednesday, February 8, 2012
3:30 PM
Physics Building, Room 204
Note special room.

## "Hydrodynamic Noise and Bjorken Expansion"

Mikhail Stephanov , University of Illinois at Chicago
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, January 25, 2012
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Measurement of the Triple Differential Cross Section of Photon plus Jet in pp Collisions at 7 TeV"

Chuanzhe Lin , University of Virginia
[Host: Bob Hirosky]
High Energy Physics Seminar
Wednesday, November 30, 2011
3:30 PM
Physics Building, Room 204
Note special room.

## "The black hole information paradox"

Samir Mathur , Ohio State University
[Host: Diana Vaman]
ABSTRACT:
Hawking showed many years ago that pair production near black holes would violate quantum mechanics. But while many relativists were convinced about information loss, string theorists hoped that small subleading corrections to Hawking's computation would invalidate his result. Recently an inequality was derived that shows that such small corrections do not in fact change Hawing's argument. What happens instead, however, is that the structure of the black hole gets altered at the horizon due to the emergence of a new length scale for quantum effects, creating states called fuzzballs. In this talk I will give an overview of these developments, which taken together give us a resolution of the information paradox.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 16, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Radio Detection of High Energy Cosmic Ray Showers"

[Host: Bob Hirosky]
ABSTRACT:
The radio detection technique for High Energy Cosmic Ray Shower detection has been investigated in this collaborative work. High Energy Cosmic Ray Showers produce disk-like ionization front which moves with relativistic speed in our atmosphere. We study the reflection of radio waves such as the ones from commercial radio and TV stations from the relativistic moving front. The reflected wave experiences a high blue-shift in frequency due to relativistic Doppler effect. The feasibility study of detection of showers via this method and the benefits will be presented.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 2, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Consistent truncations of IIB on Sasaki-Einstein manifolds and N=2 supergravity in five dimensions"

Phillip Szepietowski , UVA
[Host: Diana Vaman]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 12, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Measurement of the Differential Cross Section for Isolated Prompt Photon Production in pp Collisions at 7 TeV"

Ted Kolberg , Notre Dame
[Host: Chris Neu]
ABSTRACT:
A measurement of the differential cross section for the inclusive production of isolated prompt photons in proton-proton collisions at a centre-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 36 pb-1 recorded by the CMS detector at the LHC. The measurement covers the pseudorapidity range |η| < 2.5 and the transverse energy range 25 < ET < 400 GeV, corresponding to the kinematic region 0.007 < xT < 0.114. Photon candidates are identified with two complementary methods, one based on photon conversions in the silicon tracker and the other on isolated energy deposits in the electromagnetic calorimeter. The measured cross section is presented as a function of ET in four pseudorapidity regions. The next-to-leading-order perturbative QCD calculations are consistent with the measured cross section.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 5, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Spin Crisis and Orbital Angular Momentum> in Hadrons"

Kunal Kathuria , University of Virginia
High Energy Physics Seminar
Wednesday, May 4, 2011
3:30 PM
Physics Building, Room 204
Note special room.

## "Search for the SM Higgs Boson in Lepton plus Jets Final States"

Huong Nguyen , University of Virginia
[Host: Bob Hirosky]
High Energy Physics Seminar
Wednesday, April 27, 2011
3:30 PM
Physics Building, Room 204
Note special room.

## "Higgs boson search using diphotons at CDF"

Karen Bland , Baylor
[Host: Craig Group]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 20, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The Upsilon and the SiPM: a particle from the past and its place in current LHC physics, and a new photo sensor and its possible future in detectors."

Jake Anderson , Fermilab
ABSTRACT:
The Upsilon resonances provide a clear signal for early analysis with LHC data. As such it is ideal as a testing and calibration tool. Despite its unambiguous signal and comparatively large cross section Upsilon production at hadron colliders is not entirely understood. I will present the first Upsilon cross section measurement from CMS, and look at its place with other hadron collider experimental results and with the latest theoretical predictions. In the future, the LHC environment will place increasing challenges on the detector systems there. One promising technology utilizes pixelated APD's operating in Geiger mode to measure light intensity. Such devices have many advantages and some drawbacks. I will look at the basic application of this family of sensors in hadronic calorimetry and explore more specific applications being developed and deployed by the CMS hadronic calorimeter community.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 13, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "TBA"

Guy Moore , McGill
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Tuesday, April 12, 2011
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Joint HEP/Nuclear Seminar

Slideshow (PDF)

## "A search for resonant production of Top quarks pairs at CDF"

Yuri Oksuzian , UVa
[Host: Craig Group]
High Energy Physics Seminar
Wednesday, April 6, 2011
3:30 PM
Physics Building, Room 204
Note special room.

## "Understanding the Quark Gluon Plasma"

Christine Nattrass , University of Tennessee, Knoxville
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 30, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Little Higgs and Superlatives"

Daniel Stolarski , University of Maryland
[Host: Chris Neu]
ABSTRACT:
Little Higgs models revive the old idea of the Higgs being a pseudo-Goldstone boson. These models are motivated by the little hierarchy problem and present many interesting signatures for the LHC. In this talk I will review the Little Higgs mechanism and describe some of the models in the literature. I will then describe some of the problems with existing models, and conclude by discussing a new model that I worked on with Jesse Thaler and Martin Schmaltz (arXiv:1006.1356 [hep-ph]).
High Energy Physics Seminar
Wednesday, March 2, 2011
3:30 PM
Physics Building, Room 204
Note special room.

## "Topological Insulators, Gravity and Torsion"

Rob Leigh , University of Illinois
[Host: Diana Vaman ]
ABSTRACT:
The effective action encoding elastic transport properties of topological insulators involves effective (non-dynamical) 'gravitational' variables. In the case of 2+1-dimensional time-reversal breaking topological insulators, the leading term in the action is a 'Chern-Simons' action involving the torsion of the connection. The coefficient of this term is the dissipationless Hall viscosity, a direct analogue of the Hall conductivity. In this talk, we review the calculation of the Hall viscosity in a simple model, and discuss its interesting renormalization properties.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 23, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Fluctuation, dissipation, and thermalization in non-equilibrium AdS5 black hole geometries"

Derek Teaney , SUNY at Stony Brook
[Host: Peter Arnold]
ABSTRACT:
We give a simple recipe for computing dissipation and fluctuations (commutator and anti-commutator correlation functions) for non-equilibrium black hole geometries. The recipe formulates Hawking radiation as an initial value problem, and is suitable for numerical work. We show how to package the fluctuation and dissipation near the event horizon into correlators on the stretched horizon. These horizon correlators determine the bulk and boundary field theory correlation functions. In addition, the horizon correlators are the components of a horizon effective action which provides a quantum generalization of the membrane paradigm. In equilibrium, the analysis reproduces previous results on the Brownian motion of a heavy quark. Out of equilibrium, Wigner transforms of commutator and anti-commutator correlation functions obey a fluctuation-dissipation relation at high frequency.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 9, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Fermion Bag Approach to Lattice Field Theories"

Shailesh Chandrasekharan , Duke University
[Host: Peter Arnold]
ABSTRACT:
The solution to the fermion sign problem forces one to sum over a class of fermion configurations before a Monte Carlo algorithm can be designed. Conventionally this makes it necessary to compute the determinant of an N x N matrix at every step where N is large. Thus, it is important to optimize the value of N. Conventional approaches based on the Hubbard Stratanovich transformation set N = Volume or N = number of particles. We suggest a new approach in which N is optimized by the nature of the interactions. Effectively, the coupling is used to isolate a set of fermion degrees of freedom that interfere with each other and thus create a fermion bag. Thus, N is determined by the size of this bag. Using a simple example of the massless Lattice Thirring model we show that at both weak and strong couplings the bag size can be small. Thus, we can design algorithms that are far more efficient than the conventional algorithms in these regions of the coupling.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 2, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Setting up jet-modification as a probe of QCD media at HERA, RHIC and LHC"

Abhijit Majumder , Ohio State
[Host: Peter Arnold]
ABSTRACT:
The modification of hard jets in dense extended media such as large nuclei or a deconfined quark gluon plasma will be described in a factorized formalism where the hard partons couple weakly with the medium, where the medium may itself be strongly or weakly coupled. The effect of the medium will be parametrized in a handful of transport coefficients which are obtained as the in-medium expectation of well defined operator products. We will attempt to describe the attenuation of the yield of leading hadrons in DIS at HERA and heavy-ion collisions at RHIC as well as the centrality, azimuthal anisotropy and flavor dependence (at RHIC) in a single formalism. Also preliminary results from a new Monte-Carlo event generator based on this formalism will be presented and compared with the new LHC measurements of dijet asymmetry.
High Energy Physics Seminar
Wednesday, January 26, 2011
3:30 PM
Physics Building, Room 204
Note special room.

## "W/Z Physics at CMS"

Kristian Hahn , MIT
[Host: Chris Neu]
ABSTRACT:
In this talk I discuss recent measurements of the Z ---> l+l- and W ---> lv inclusive cross-sections performed by the CMS collaboration. W and Z gauge boson production has been among the first physics studied at the LHC and the CMS results are an important test of Standard Model predictions at the unprecedented pp center-of-mass collision energy of 7 TeV. Events are selected for the analysis by requiring the presence of energetic, isolated electrons or muons. The presence of an energetic neutrino is demonstrated using the distribution of missing transverse energy. I describe the criteria used for lepton identification, as well as the data-driven techniques employed in the estimation of efficiencies, in the tuning of Monte Carlo simulation and in the determination of the most important background contributions. I discuss the methods used to evaluate experimental uncertainties and present relevant kinematic distributions and the extracted cross-sections.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, January 19, 2011
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Jet energy loss and stopping distances in weakly-coupled quark-gluon plasma"

Wei Xiao , University of Virginia
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, December 1, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The Large Limits of QCD"

Thomas Cohen , University of Maryland
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 17, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Dynamical Electroweak Symmetry Breaking in the Standard Model with a Heavy Fourth Generation"

Chi Xiong , University of Virginia
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 10, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The Jarzynski Identity and the AdS/CFT Duality"

Djordje Minic , Virginia Tech
[Host: Diana Vaman]
ABSTRACT:
I will discuss a remarkable analogy between the Jarzynski identity from non-equilibrium statistical physics and the AdS/CFT duality. I will apply the logic that leads to the Jarzynski identity to renormalization group (RG) flows of quantum field theories and then argue for the natural connection with the AdS/CFT duality formula. This application can be in principle checked in Monte Carlo simulations of RG flows. Given the existing generalizations of the Jarzynski identity in non-equilibrium statistical physics, and the analogy between the Jarzynski identity and the AdS/CFT duality, we are led to suggest natural but novel generalizations of the AdS/CFT dictionary. The talk is based on arXiv:1007.3970 (with Michel Pleimling).
High Energy Physics Seminar
Wednesday, October 20, 2010
3:30 PM
Physics Building, Room 204
Note special room.

## "Low-Mass Dimuons at CDF: Dark Forces, Higgs Bosons, and Data Anomalies"

Chris Hays , Oxford University
[Host: Chris Neu]
ABSTRACT:
Various studies of collider and cosmological data have found multilepton sources that are not well described by the usual models. These studies have motivated a theory of a new force at the O(1 GeV) energy scale that interacts with standard-model particles only through a high-mass intermediary. This new 'dark' force could produce multiple leptons at small angles, dubbed 'lepton jets,' at hadron colliders. I describe a general CDF search for high-momentum muon pairs with sensitivity to any new low-mass resonance. I also briefly discuss the possibility that the Higgs boson is a source of high-momentum dimuons, with a mass lower than the usual LEP bounds and more consistent with supersymmetry and the global electroweak fits.
High Energy Physics Seminar
Wednesday, May 5, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Chaolun Wu , University of Virginia
[Host: Diana Vaman]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 28, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Searching for Gauge-Mediated Supersymmetry Breaking in the Large Hadron Collider's First Events"

Rachel Yohay , University of Virginia
High Energy Physics Seminar
Wednesday, April 21, 2010
3:30 PM
Physics Building, Room 204
Note special room.

## "Spear-fishing at the LHC -- Using Weak Bosons to Understand Proton Structure at High Energy"

Jeremy Mans , University of Minnesota
[Host: Bob Hirosky]
ABSTRACT:
With the LHC recently having achieved collisions at a world-record center of mass energy of 7 TeV, particle physics is moving into a new era. The collision environment at the LHC is determined by the accelerator but also by the structure of the proton. The LHC will probe smaller momentum fractions with higher momentum transfers than any previous collider. I will discuss some of the planned techniques to study and constrain the proton structure using electroweak bosons as probes in LHC collisions. These measurements are a key component to our understanding of the backgrounds to possible new physics signatures and also have relevance for constraining the explanations for any new observation.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 14, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "TBA"

Guy Moore , McGill
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Monday, April 12, 2010
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Joint HEP/Nuclear Seminar

Slideshow (PDF)

## "Search for Lepton Flavor Violating decay Bs (Ks μ Â± e ∓ )"

Emmanuel Munyangabe , University of Virginia
[Host: Craig Dukes]
ABSTRACT:
Standard Model theory does not allow Lepton Flavor Violating (LFV) decays, however other extensions like SUSY, Pati-Salam Lepto-Quark (LQ) and Extra-Dimension(ED) models allow the LFV decays. In these models, the assumption of a local gauge symmetry between quarks and leptons at the lepton-flavor violation tree-level couplings lead to the prediction of a new force of nature which mediates transitions between quarks and leptons, hence LFV searches are important tool to search for New Physics beyond SM. I will discuss about the progress I have made in the search for the mentioned decay using data collected by D0 detector at Tevatron.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 31, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Search for WZ in the l nu b bbar Final State at CDF"

Justin Keung , University of Pennsylvania
[Host: Chris Neu]
ABSTRACT:
An important search channel for the Higgs boson is associated WH production with subsequent decays of W -l nu and H -b bbar. The identification of b-quark jets is an important component in this search. We discuss the commissioning of a new artificial neural network b-quark jet identification algorithm. The resulting final state is shared with standard model WZ production which necessarily must be well-understood. We discuss an important cross-check of the WH search which is to apply the same techniques to measuring the WZ contribution to our event candidate sample.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 24, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "High energy QCD and the Glasma"

Raju Venugopalan , Brookhaven National Lab
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 17, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Introduction to AdS/CFT and its applications"

Eddy Barnes , University of Virginia
[Host: Diana Vaman]
ABSTRACT:
The anti-de-Sitter space/conformal field theory (AdS/CFT) correspondence is a powerful tool in the study of conformal field theories, which are ubiquitous in High Energy and in the study of phase transitions in Condensed Matter (CM) and cold atomic systems. AdS/CFT is a conjectured duality that maps a CFT without gravity to a string theory on a curved space. In regimes where the CFT is most difficult to solve, the string theory tends to be simple, effectively reducing to Einsteinâs gravity theory. I will begin with an extensive introduction to the basic features of AdS/CFT. I will describe some of my own research using it in the context of scattering amplitudes and time-dependent thermal processes. I will also discuss some of the exciting new applications to CM and cold atomic systems and conclude with possible future directions along these lines.
High Energy Physics Seminar
Wednesday, January 20, 2010
3:30 PM
Physics Building, Room 204
Note special room.

Joint HEP / CM Seminar

## "Collider and Flavor Phenomenology in the Scalar sector of Warped Extra Dimensions"

Manuel Toharia , University of Maryland
[Host: Diana Vaman]
ABSTRACT:
I will review and present new results regarding the phenomenology of the two (presumably) lightest scalars in the context of warped extra dimensions: the Higgs and the radion. This last one, could be the lightest "new physics" state to be discovered at the LHC in this type of models. Its phenomenology is very similar to the Standard Model (SM) Higgs. When SM fields are allowed to live in the bulk of the extra dimension, new interesting effects appear in the scalar sector of the model. In particular, both the Higgs and the radion can now typically mediate Flavor Changing Neutral Currents at tree level. These will impose bounds on the flavor structure of the model, but also allow for interesting probes in current and future collider experiments.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, December 2, 2009
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Closing in on the Higgs Boson"

Lidija Zivkovic , Columbia University
[Host: Bob Hirosky]
ABSTRACT:
The Standard Model describes the unification of electromagnetic and weak interactions. It was thoroughly tested over past thirty years, and represents one of the major successes of modern physics. This theory predicted the existence and the masses of the weak bosons. The last remaining piece of the puzzle is the Higgs boson whose existence is crucial for our understanding of the origin of particle masses. Direct searches at LEP put a lower limit on the Higgs boson mass, and together with precision measurement constrained it to <~200 GeV. The D0 and CDF experiments at the Tevatron recently excluded a new interval in the Higgs mass. In this time when we are entering LHC era, we are coming closer to the discovery or exclusion of the SM Higgs boson. I will discuss current searches for the SM Higgs boson with the D0 experiment at Tevatron, highlighting the most important techniques. I will also draw a parallel with future searches at LHC, showing what we can learn from Tevatron experience.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 18, 2009
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Flavor-branes in gauge/string duality and M-theory"

Johannes Schmude , Swansea University
[Host: Diana Vaman]
ABSTRACT:
Over the last years, gauge/string duality has been extended to include gauge theories with an arbitrary number of flavors. We study the flavoring procedure in the light of calibrated geometry and discuss the special case of a type IIA dual of N=1 super Yang-Mills with flavors. Relating our results to the standard type IIA/M-theory duality, we find that the usual oxidation formulas cannot accommodate for the additional flavor branes. We address and solve this issue by considering M-theory with torsion, which allows us to construct source-modified equations of motion for eleven-dimensional supergravity.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 4, 2009
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Reorganizing the QCD pressure at intermediate coupling"

Michael Strickland , Gettysburg College
[Host: Peter Arnold ]
ABSTRACT:
The perturbative expansion of the pressure of QCD is known to order g^6 log(g), however, the resulting series is poorly convergent at phenomenologically relevant temperatures/couplings. I will discuss a method for improving the convergence of the successive approximations to the QCD pressure in a systematic manner which exactly reproduces the perturbative series in the weak-coupling limit. The method relies on folding in information about the correct high-temperature degrees of freedom via the hard-thermal-loop (HTL) resummation scheme. In order to give some background I will also discuss the poor convergence of quantum mechanics for the ground state of an anharmonic oscillator and present results for the three loop HTL-improved pressure of QED. Finally, I will present new results of an HTL-improved calculation of QCD thermodynamics to three-loops and critically discuss how this compares to available lattice data.
SLIDESHOW:
High Energy Physics Seminar
Tuesday, October 27, 2009
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Joint HEP/Nuclear Seminar

Slideshow (PDF)

## "Development of a Digital Hadron Calorimeter"

Jose Repond , Argonne National Laboratory
[Host: Craig Dukes]
ABSTRACT:
We present the concept of a Digital Hadron Calorimeter (DHCAL) for use in a detector optimized for the application of Particle Flow Algorithms to the measurement of jet energies. Resistive Plate Chambers (RPCs) with 1 x 1 cm^2 readout pads are used as active elements. The front-end electronic readout is integrated on the pad-boards of the chambers and applies a single threshold (1-bit) to the signal charges, hence the designation of digital readout. We report on detailed measurements with a small scale prototype in the Fermilab test beam using muons, positrons, pions, and protons and in the laboratory using cosmic rays. The results validate the concept and serve as basis for the design of a large prototype calorimeter. An update on the ongoing construction of the latter will be given.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 21, 2009
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Studies of D -> pi e nu and D -> K e nu at CLEO-c"

Laura Fields , Cornell University
[Host: Craig Dukes]
ABSTRACT:
Many precision tests of the Standard Model require input from Lattice QCD (LQCD). Of particular importance are the semileptonic form factors used to extract Vub in semileptonic B decays. Similarities between the D and B sector make charm semileptonic decays an excellent testing ground for the increasingly precise predictions of LQCD. CLEO-c has recently used its entire data sample to produce a set of measurements involving the decays D0 Ã¢â â pi e nu, D0 Ã¢â â K e nu, D+ Ã¢â â pi0 e nu and D+ Ã¢â â K0 e nu. These results, which include the worlds most precise branching fraction and D -> pi form factor measurements, will be discussed.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 14, 2009
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Search for electron antineutrinos from the Sun with KamLAND detector"

Oleg Perevozchikov , University of Tennessee
[Host: Craig Dukes]
ABSTRACT:
I will present the results of the search for the electron antineutrinos from the Sun with Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND). There is no known direct production of the electron antineutrinos in the Sun. However, in the some theoretical models with the large neutrino magnetic moment antineutrinos from the Sun can be produced e.g. via Spin Flavor Precession mechanism (SFP). Search for solar antineutrinos potentially can provide new information about fundamental properties of neutrinos. The most sensitive one-kiloton antineutrino detector KamLAND gives the possibility to search for such antineutrinos. The analysis described in this dissertation is based on 1425.9 days of data collection in KamLAND. The search for the electron antineutrinos have been made within 8.8-16.3MeV antineutrino energy range, that is above energies of reactor antineutrinos and where properties of the solar B8 neutrinos are well studied. Based on the number of observed candidates and estimated background rates the upper limit on the electron antineutrino flux and probability of conversion electron neutrinos produced in the Sun to electron antineutrinos was set. The same limit can be used on the diffuse Supernovae neutrino flux. The estimated background rates during this study can make significant impact on the design of the future neutrino scintillator detectors.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 7, 2009
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Commissioning and Status of the ATLAS pixel detector at the LHC"

Eugene Galyaev , CERN
[Host: Craig Dukes]
ABSTRACT:
The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN. With approximately 80 million readout channels, the ATLAS silicon pixel detector is high-acceptance, high-resolution, low-noise tracking device providing the desired refinement in charged track pattern recognition capability in order to meet the stringent track reconstruction requirements of ATLAS, largely defining its ability to effectively resolve primary and secondary vertices and perform efficinet flavor tagging essential for discovery of new physics. Being the last sub-system installed in ATLAS by the end of June 2007, Pixel Detector was successfully connected, commissioned, and tested in situ while meeting an extremely tight operations schedule, and is ready to take data upon the projected turn-on of the LHC at the end of 2009. UT Dallas group has successfully deployed and commissioned the environmental controls for the opto-links, crucial for stable operation of the readout electronics of the pixel detector. Since fall 2008, Pixel Detector was included in the combined ATLAS detector operation, collecting physics data with cosmic muons. Details from the Pixel Detector installation and commissioning, as well as the details on major calibration procedures and the results obtained with collected cosmic data, are presented along with the current ATLAS detector status summary.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, September 23, 2009
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The Search for Neutralino Dark Matter with the AMANDA Neutrino Telescope"

Ralf Ehrlich , University of Maryland
[Host: Craig Dukes]
ABSTRACT:
There is convincing indirect evidence based on cosmological data that approximately one quarter of the universe is made of dark matter. However, to this date there is no direct detection of the dark matter and its nature is unknown. Many theories suggest that dark matter is made of supersymmetric particles, and the most promising candidate out of the supersymmetric particles is the lightest neutralino. These neutralinos can get gravitationally trapped in the Earth, where they eventually annihilate. The annihilation products decay and a fraction of the decay products are muon-neutrinos, which can be detected with the AMANDA/IceCube neutrino telescope in the ice at the South Pole. Neutrinos cannot be detected directly. However, there is a small possibility that they interact with the nuclei of the ice via a charged current interaction and "create" charged leptons. These charged leptons continue to travel in almost the same direction as the neutrinos. As long as their speed is higher than the speed of light of the ice, they emit Cherenkov radiation which can be captured by photomultipliers installed inside the ice. A hypothetical muon-neutrino flux from neutralino annihilations inside Earth should show up as an excess over the expected muon-neutrino flux from atmospheric neutrinos produced in the northern hemisphere. No significant excess has been observed, yielding an upper limit on the neutrino flux that could have come from neutralino annihilation.
High Energy Physics Seminar
Thursday, September 17, 2009
4:00 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

## "QCD Physics at CMS"

Nikos Varelas , Univ. of Illinois, Chicago
[Host: Bob Hirosky]
ABSTRACT:
The Large Hadron Collider (LHC) at CERN will soon be at the frontier of experimental High Energy Physics. It is expected to start colliding proton-proton beams later this year at an initial center-of-mass energy of 10 TeV. It will be a unique tool for fundamental physics research with an unprecedented physics potential,probing distances down to 10 (-20) m. In this talk, I will discuss the potential of the Compact Muon Solenoid Detector (CMS), one of four experiments at the LHC, to study the fundamental theory of the strong interactions â Quantum Chromodynamics (QCD) â using a variety of final states and observables with the first experimental data.
High Energy Physics Seminar
Wednesday, August 26, 2009
3:30 PM
Physics Building, Room 204
Note special room.

## "H->WW*->mu+nu+j+j : A Single Channel's Search for the Higgs at the Tevatron"

Shannon Zelitch , University of Virginia
[Host: Bob Hirosky]
High Energy Physics Seminar
Wednesday, April 22, 2009
3:30 PM
Physics Building, Room 204
Note special room.

## "Lasers"

O. Pfister,C. Sackett, K. Williams, S. Wolf , University of Virginia
[Host: Mike Timmins]
ABSTRACT:
The 15th annual physics demonstration sow will be held Wednesday evening, April 22nd, 2009 in room 203 of the physics building at the University of Virginia to celebrate National Physics Day. This highly anticipated event is a special family oriented physics demonstration show for the general public. The show this year will be at 7:00 p.m. in the physics building on McCormick Road. Parking is available in the parking garage on Emmett Street, or after 5:00 p.m. in the football stadium parking lots. Physics professors Olivier Pfister, Cass Sackett, Keith Williams, Stuart Wolf and Mike Timmins will delight the crowd with strange and mystifying events. When the laser was first invented in 1958, it was immediately considered a âsolution waiting for a problemâ. Well, that was a long time ago and we have since found many problems that the laser is a perfect solution for. In fact, lasers are ubiquitous in everyday modern electronics from simple pointing instruments to cd/dvd players. However, lasers are even more useful to researchers and after this show, you will begin understand why. The demonstrations are designed to intrigue and excite both young and old from novice to expert. Bring your family and friends, but come on time as the room fills up quickly. For more information about this free public event, call 924-3781.
High Energy Physics Seminar
Wednesday, April 22, 2009
7:00 PM
Physics Building, Room 203
Note special time.
Note special room.

Physics Day Show

## "J/ ψ Production Studies in CMS"

Zongchang Yang , Peking University - CMS
[Host: Chris Neu]
ABSTRACT:
When the LHC starts its operation, it will produce large number of charm quarks even in low luminosity runs during the first few years of running. With precision tracking and nearly complete muon coverage, the CMS detector is well suited to the study of quarkonium through its di-muon decays. We report the methods and plans for measuring the differential p T J/ ψ → μ+μ− production cross section, using data to be collected in the first LHC run by the CMS detector.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 1, 2009
3:30 PM
HEP, Room 123
Note special room.

Slideshow (PDF)

## "Observation of the rare charmed B decay, Bd to D*+ a0-, at the BaBar experiment: On finding a needle in a haystack."

Hella Snoek , University of Amsterdam/NIKHEF - BaBar
[Host: Chris Neu]
ABSTRACT:
A general introduction is presented into the field of B-meson physics, the BaBar experiment, and the motivation for the branching ratio measurement of the B-meson decay Bd->D*a0. The branching ratio of this decay is sensitive to non-factorizing terms of QCD factorization, which is generally used to calculate the amplitudes of meson decays. Second, this decay can be extremely sensitive to the CKM-angle gamma, the least accurately known angle of the CKM Unitarity Triangle. An experimental challenge of this measurement is posed by the low expected branching ratio of the decay (order 10-6), in combination with the high background levels from related B-meson decays. The analysis uses more than 30 selection variables and an unbinned likelihood fit performed simultaneously in three observables. The optimization procedure of the data selection and the setup of the likelihood fit are presented in the talk. The both promising and remarkable results of the branching ratio measurement are discussed.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 25, 2009
3:30 PM
HEP, Room 123
Note special room.

Slideshow (PDF)

## "Recent results of the photon plus heavy flavor jet cross sections at D0"

Daniel Duggan , Florida State University - D0
[Host: Chris Neu]
ABSTRACT:
Photons produced in association with heavy flavor quarks provide a unique window into both the sea quark content of the proton and the splitting of gluons into heavy flavor quark pairs. A new combination of experimental techniques at the Tevatron has provided the basis for the first measurements of the differential photon plus heavy flavor jet production cross sections at 1.96 TeV. Results of these measurements and comparisons to next-to-leading order theoretical predictions will be presented.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 18, 2009
3:30 PM
HEP, Room 123
Note special room.

Slideshow (PDF)

## "Measurement of the Inclusive Isolated Prompt Photon Cross Section at CDF"

Carolina Deluca , IFAE - CDF
[Host: Chris Neu]
ABSTRACT:
I present results on the measurement of the inclusive direct photon production cross section in proton-antiproton collisions at #sqrt(s) = 1.96 TeV, using data collected with the upgraded Collider Detector at Fermilab in Run II, and corresponding to an integrated luminosity of 2.5 fb-1. Measurements are performed as a function of the photon transverse momentum for photons with pT > 30 GeV and |eta| < 1.0. Photons are required to be isolated in the calorimeter (isolation ET < 2 GeV). We use the calorimeter isolation distribution to estimate the contamination from jets faking isolated photons. The measured cross section is corrected back to the hadron level and compared to NLO pQCD predictions. The NLO pQCD predictions include non-perturbative corrections. We find good agreement between data and the theoretical predictions.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 11, 2009
3:30 PM
HEP, Room 123
Note special room.

Slideshow (PDF)

## "Beauty in photoproduction at HERA"

Sarah Boutle , University College London, ZEUS
[Host: Chris Neu]
ABSTRACT:
I will present a recent ZEUS measurement of beauty photoproduction in dijet events at HERA. In the analysis, b-quark events are identified in the semi-leptonic decay mode using a technique which exploits the long lifetime of the B hadron. This is the first measurement of its kind at ZEUS as it uses the Micro-Vertex Detector (MVD), an upgrade made to ZEUS for the HERA II running period. I will describe the analysis method involved in the measurement and then present the results which include beauty production cross sections as well as dijet correlations. The results are compared to QCD predictions and previous measurements.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 18, 2009
3:30 PM
HEP Building, Room 123
Note special room.

Slideshow (PDF)

## "Single Top Searches at Dzero"

Ernest Aguilo , York University
[Host: Chris Neu]
ABSTRACT:
Great improvements have been made since the evidence of single top quark production at DZero in 2006 with 1 fb-1 of data. Here I present the signal and background modeling, event selection, multivariate techniques and statistical tools for the measurement of the cross section using 2.3 fb-1 of data.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 11, 2009
3:30 PM
HEP Building, Room 123
Note special room.

Slideshow (PDF)

## "CP Violation for the Heaven and the Earth - - - Sighting the 4th Generation?"

W.S. Hou , National Taiwan University
[Host: PQ Hung]
SLIDESHOW:
High Energy Physics Seminar
Monday, February 2, 2009
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Slideshow (PDF)

## "LAr calorimeter commissioning and search for a light stop"

Zhayou Yang , Carleton University
[Host: Chris Neu]
ABSTRACT:
Extensive tests have been carried out with the ATLAS liquid argon( LAr) calorimeter system. This talk presents the highlights of the LAr commissioning activities. Supersymmetry searches at ATLAS are summarized, with a focus on the search for a light supersymmetric top squark (stop). A light stop is motivated by theories of electroweak baryogenesis in the Minimal Supersymmetric Standard Model (MSSM). An MSSM benchmark point, LST1, with a stop mass of 150 GeV is investigated for potential discovery with the ATLAS detector.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, January 28, 2009
3:30 PM
Physics Building, Room HEP 123
Note special room.

Slideshow (PDF)

## "Standard Model Higgs Searches with D0 in RunII"

Michael Kirby , Northwestern University
[Host: Chris Neu]
ABSTRACT:
The Higgs boson is the last missing particle within the Standard Model of particle physics and the largest focus of research efforts at the Fermilab Tevatron collider. The combination of the searches for the Standard Model Higgs boson at a center-of-mass energy of sqrt(s)=1.96 TeV using up to 4 fb^-1 of data collected with the D0 detector will be presented. The major contributing processes include associated production (WH->l+nu+b+b, ZH->nu+nu+b+b, ZH->l+l+b+b, and WH->WWW^(*)) and gluon fusion (gg->H->WW^(*)). The significant improvements across the full mass range resulting from the larger data sets, improved analyses and inclusion of additional channels are discussed. The prospects for expanding the Higgs sensitivity region though the end of Tevatron operation will also be discussed.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, December 3, 2008
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Jet Shapes Studies at CMS"

Pelin Kurt , Kurkova University
[Host: Chris Neu]
ABSTRACT:
The CMS (Compact Muon Solenoid) detector will observe high transverse momentum jets produced in the final state of proton-proton collisions at the center of mass energy of 14 TeV. These data will allow us to measure jet shapes, defined as the fractional transverse momentum distribution as a function of the distance from the jet axis. Since jet shapes are sensitive to parton showering processes they provide a good test of Monte Carlo event simulation programs. A potential method was investigated to measure jet shapes in CMS using reconstructed calorimeter energies where the statistics of all distributions correspond to a CMS data set with 10 pb -1 of integrated luminosity. We compare the predictions of the Monte Carlo generators PYTHIA and HERWIG++.
High Energy Physics Seminar
Thursday, November 13, 2008
3:30 PM
HEP Building, Room 123
Note special date.
Note special room.

## "Top Production at the Tevatron"

Tom Schwarz , Univ. of California-Davis
[Host: Chris Neu ]
ABSTRACT:
I will present the latest results from CDF in the study of top quark production. A little over a decade after the discovery of the Top quark the Tevatron has now produced over 10 times the statistics of the first experiment . Because of this, we are finally now able to precisely test the top quarks place in the Standard Model. In the same amount of time it took to collect this data, measurement techniques have advanced at a similar pace. I will discuss two new state-of-the-art measurements with the latest data of the top quark cross section. These new measurements are the first to reach the precision of the theoretical cross-section, and have managed to resolve a long-standing discrepency between previous measurements. In addtion, a new measurement, the forward backward asymmetry is discussed. The measurement is a test of discrete symmetries at very high energy, which has recently received a sizable amount of attention because of an unexpectedly large measured value.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, November 12, 2008
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Search for Higgs Bosons Produced in Association with W Bosons at CDF"

Jason Slaunwhite , Ohio State University
[Host: Chris Neu]
ABSTRACT:
The Higgs boson is a result of electroweak symmetry breaking in the Standard Model. The Higgs is experimentally unobserved, despite the Standard Model's prediction of it's existence. We present a search for a Standard Model Higgs bosons produced in association with a W bosons in proton anti-proton collisions recorded at CDF. Our search uses a dataset corresponding to an integrated luminosity of 2.7/fb. Our candidate events have one high-momentum muon or electron, missing ET, and a Higgs that decays to a pair of b-quarks jets. We extended the reach of the search by including events without a triggered lepton. We employ several b-quark identification algorithms to enhance the purity of Higgs events. An Artificial Neural Network improves our discrimination of Higgs signal kinematics from background processes such as top pair production and W+jets. We perform a likelihood fit of the neural network output distribution and set 95% confidence level upper limit on the associated production cross section times branching ratio as a function of Higgs mass.
High Energy Physics Seminar
Tuesday, October 28, 2008
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Brane Tilings, CS Theories, and M2 Branes"

Amihay Hanany , Imperial College
[Host: Diana Vaman]
High Energy Physics Seminar
Monday, October 27, 2008
3:30 PM
Physics Building, Room 313
Note special date.
Note special room.

## "Study of Charmless Inclusive Semileptonic B Decays and Measurement of the CKM Matrix Element |Vub| with the BaBar Detector"

Virginia Azzolini , IFIC-University of Valencia
[Host: Chris Neu]
ABSTRACT:
The determination of the element |Vub| of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix plays a central role in the search for flavour and CP violation beyond the Standard Model. In this seminar, we will present measurements of partial branching fractions for inclusive charmless semileptonic decays, B -> Xu l nu, in limited regions of phase space and the corresponding values of |Vub|, as extracted using several theoretical calculations. The invariant mass of the hadronic system, Mx, the squared invariant mass of the lepton pair, q2, and the variable P+ = Ex-|Px|, or one of their combinations, in the process B -> Xu l nu are used as discriminating variables to suppress semileptonic decays with charm. Partial branching fractions are measured as functions of the cuts on the above variables. Different theoretical models are used to compute acceptances and related uncertainties, thereby allowing to extract |Vub|. > These studies are performed on a sample of 383 million BB events collected at the ÃÂ¥(4S) resonance, with the BaBar detector at the PEP-II e+e- storage rings
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 22, 2008
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Search for new physics with b-quark jets"

Viktor Veszpremi , Cornell University
[Host: Christopher Neu]
ABSTRACT:
The new energy regime and higher data-taking rate of the LHC will soon extend the possibilities of searches for yet undiscovered particles and phenomena. Final states produced via b-quark decays are often created by physics beyond the standard model; they are also favored in light standard model Higgs boson processes. High-pt B-tagging, therefore, has been and continues to be one of the most important tools in searches both at the Tevatron and at the LHC. In the first half of my presentation, I will introduce the CMS pixel detector, a component of the CMS tracking system that is vital for B-tagging, and talk about the on-going calibration efforts in its commissioning. In the second half of my presentation, I will demonstrate the use of B-tagging in physics analyses through an example of a low-mass standard model Higgs boson search perfomed in the CDF experiment at the Tevatron.
High Energy Physics Seminar
Wednesday, October 15, 2008
3:30 PM
Physics Building, Room 120
Note special room.

## "Measuring Fully Leptonic Charged B Decays in the Recoil of Semileptonic B Decays at BaBar"

Luke Corwin , Ohio State University
[Host: Chris Neu]
ABSTRACT:
After a brief review of the theoretical predictions and experimental difficulties presented by fully leptonic charged B decays, I will review the latest search for charged B decays into lepton neutrino pairs, where the lepton can be an electron, muon, or tau, in the recoil of a semileptonically decaying charged B. This search uses the full data set collected at the BaBar experiment.
High Energy Physics Seminar
Wednesday, October 8, 2008
3:30 PM
Physics Building, Room 204
Note special room.

## "The CLEAR Experiment: Measuring Neutrino-Nucleus Coherent Scattering at the Spallation Neutron Source"

Kate Scholberg , Duke University
[Host: Craig Dukes]
ABSTRACT:
A low-threshold neutrino scattering experiment at a high intensity stopped-pion neutrino source has the potential to measure coherent neutral current neutrino-nucleus elastic scattering. This process has never been observed and presents opportunities for new tests of the Standard Model. A promising prospect for the measurement of this process is a proposed noble-liquid-based experiment called CLEAR (Coherent Low Energy A(Nuclear) Recoils), at the Spallation Neutron Source. This talk will describe the CLEAR experiment and its physics reach.
High Energy Physics Seminar
Wednesday, September 17, 2008
3:30 PM
Physics Building, Room 204
Note special room.

## "Search for the Standard Model Higgs Boson at CDF Run II"

Brandon Parks , Ohio State University
[Host: Chris Neu]
ABSTRACT:
One of the greatest theoretical triumphs in the history of physics has been the unification of the electromagnetic and weak forces. This theory successfully predicted the masses of the W and Z bosons which were later measured at CERN, and involves a mechanism that provides all particles with mass. This mechanism also predicts the existence of another observable particle, known as the Higgs boson. Experiments at the LEP collider have placed a lower bound on its mass of 114 Gev/c2, but direct measurement of the Higgs has thus far eluded all efforts. Currently, the CDF and D0 experiments at Fermilab are pushing to probe the mass regions not excluded by LEP with a number of analyses optimized for masses extending from 100 to 200 GeV/c2. Near the LEP boundary where the Higgs is expected to decay primarily to a pair of bottom quarks, the most promising channels involve Higgs produced in association with a W or Z boson. In particular, the ZH modes have very interesting properties which can be taken advantage of at the analysis level. The mode in which the Z decays to electrons or muons is extremely "clean", as leptons from vector boson decay are typically well measured and all final state particles are directly reconstructed. Conversely, the mode in which the Z decays to neutrinos is extremely challenging, as the presence of the Z can only be inferred from momentum imbalance provided by recoil with the Higgs. Utilizing new analysis techniques developed to isolate a Higgs signal amongst its seemingly overwhelming backgrounds, no significant excess of signal has currently been observed. However, limits have been set on the production cross section of a Higgs boson. Currently, limits of 16 times the standard model expectation has been set in the ZH->llbb mode, and 8 times the standard model expectation in the ZH->vvbb mode for a Higgs mass of 115 GeV/c2. Combining these results with all low mass analyses at CDF and D0, the Tevatron has placed a limit of 3.7 times the standard model expectation directly above LEP's lower mass limit.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, September 3, 2008
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Leptogenesis in a model of dark energy and dark matter"

Huicheng Guo , University of Virginia
[Host: Bob Hirosky]
High Energy Physics Seminar
Wednesday, May 7, 2008
3:30 PM
Physics Building, Room 204
Note special room.

## "Light charged Higgs at the beginning of the LHC era"

Enrico Lunghi , Fermilab
[Host: Bob Hirosky ]
ABSTRACT:
I will review the experimental evidence and theoretical biases that point to physics beyond the Standard Model. In the context of realistic supersymmetric models, I will explore in detail some interesting theoretical issues and investigate whether existing experimental constraints still allow for a light extended Higgs sector. Predictions at Tevatron and LHC in such scenarios are explored.
High Energy Physics Seminar
Wednesday, April 16, 2008
3:30 PM
Physics Building, Room 204
Note special room.

## "Search for Evidence of Neutralinos at the LHC"

Michael Balazs , University of Virginia
[Host: Bob Hirosky]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 2, 2008
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Searches for New Physics at the Tevatron"

Patrice Verdier , IPN-Lyon
[Host: Bob Hirosky]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 19, 2008
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "How Statistics Just Might Improve Your Experiment"

Jim Linnemann , Michigan State University
[Host: Bob Hirosky]
ABSTRACT:
I report on two topics presented at the PHYSTAT 2007 conference at CERN. 1) Event weighting has long been used, but is typically maligned (under the rubric of the "method of moments") as statistically inefficient (producing parameter estimates with worse uncertainty) compared to maximum likelihood fitting. However, event weighting is quite fast, requiring only one pass through the data with no iteration. Further, it has fairly recently been understood that the choice of weight function has a substantial effect on the errors, and by choosing to minimize the parameter error via calculus of variations, near-ideal uncertainty can result. 2) Evaluation of systematic errors in MC is a tedious fact of life; it's slow. We have for generations done it one variable at a time. However, it turns out that doing so makes us blind to certain systematic effects--even when the systematic errors themselves are uncorrelated. And it also turns out that statisticians knew about this since the 1920's. I'll show what our method blinds us to.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, February 6, 2008
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Signals for Composite Higgs models in top/W/Z physics"

Kaustubh Agashe , University of Maryland
[Host: Bob Hirosky]
ABSTRACT:
In the first part of the seminar, I will briefly review how the idea of the Higgs boson being a composite particle of new strong dynamics can explain the hierarchy between the Planck and weak scales and how quarks and leptons being partially composite accounts for their basic structure as well. I will argue that the largest experimental signals for such a scenario arise in the top/W/Z sectors. Remarkably, this scenario might have a dual and more useful description in terms of a warped higher dimensional spacetime. So, in the second part of the seminar, I will focus on computing signals for such composite Higgs models at the upcoming Large Hadron Collider using the extra dimensional description. Specifically, I will consider detection of the excitations (called Kaluza-Klein modes) of the gluon and graviton in the extra dimension.
High Energy Physics Seminar
Wednesday, October 24, 2007
3:30 PM
Physics Building, Room 204
Note special room.

## "Results on mixing, Δ Γ s and related CP violation in B s meson system at Tevatron"

Dmitri Tsybychev , Stony Brook
[Host: Bob Hirosky]
ABSTRACT:
The CDF and D0 experiments have collected large samples of hadronic and semileptonic decays of B s mesons. We present the latest results from the Tevatron on the measurement of mixing parameter Δ m s and the width difference between B H s and B L s and the latest results on indirect CP violation in the B s meson system.
High Energy Physics Seminar
Wednesday, October 17, 2007
3:30 PM
Physics Building, Room 204
Note special room.

## "Evidence for D0-D0bar Mixing"

Milind V. Purohit , South Carolina
[Host: E. Craig Dukes]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, October 3, 2007
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "The search for K L 0 -> π 0 π 0 μ + μ - and K L L -> π 0 μ + μ - "

David Phillips , University of Virginia
[Host: E. Craig Dukes]
ABSTRACT:
Although the neutral kaon system has been researched many times in the past, it still remains a vital tool for decisive studies on CP violation and for probing into new physics. The KTeV experiment has played a crucial role in these endeavors with an intense source of high energy kaon decays coupled with a high precision detector. Currently, there's no published calculation inside the Standard Model for Br(K L 0 -> π 0 π 0 μ + μ - ), although the decay is possible via a virtual photon or a 'possible' new neutral boson X 0 , which was recently observed by the HyperCP Experiment in the decay Σ + -> pX 0 -> p μ + μ - . The decay K L L -> π 0 μ + μ - is also an intriguing study since it contains a direct CP violating parameter. I shall report on the progress made in analyzing these two decays.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, May 2, 2007
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Discovery of Σb"

Petar Maksimovic , John Hopkins University
ABSTRACT:
In recent months, the Tevatron reached a significant milestone and delivered over one fb-1 to both the D0 and CDF experiments. The large sample of data and a powerful displaced vertex trigger combine to give CDF the worldâs largest sample of fully reconstructed Λb0s. Using this sample, we observe four new Λb0 π+/- resononances, consistent with the hypothesis of the lowest-lying Σb* baryon states.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 18, 2007
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Non-Abelian Plasma Instabilities"

Po-Shan Leang , University of Virginia
[Host: E. Craig Dukes]
High Energy Physics Seminar
Wednesday, April 11, 2007
3:30 PM
Physics Building, Room 204
Note special room.

## "Hamiltonian approach to Yang-Mills theories in 2+1 dimensions: glueball and meson mass spectra"

Alexandr Yelnikov , Virginia Tech
[Host: Peter Arnold]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, April 4, 2007
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Testing Time Reversal Invariance in Neutron Beta Decay"

Pieter Mumm , NIST
[Host: Blaine Norum]
ABSTRACT:
Neutron beta decay is the simplest of all nuclear beta decay. Its simplicity allows properties of neutron decay to be related directly to the weak coupling constants and thus precision measurements of neutron decay correlations and lifetime offer both sensitive checks of the Electroweak Standard Model as well as excellent probes of new physics. One question of intense interest is the nature of the observed baryon-antibaryon asymmetry of the universe. In this talk I will focus on a sensitive search for new time reversal invariance violating physics which offers the potential of illuminating this mystery.
SLIDESHOW:
High Energy Physics Seminar
Wednesday, March 28, 2007
3:45 PM
Physics Building, Room 204
Note special time.
Note special room.

Special Colloquium

Slideshow (PDF)

## "Polarization Transfer in 4He(e,e'p): Is the Ratio G_Ep/G_Mp Modified in the Nuclear Medium?"

Steffen Strauch , University of South Carolina
[Host: Simonetta Liuti]
High Energy Physics Seminar
Wednesday, February 28, 2007
3:30 PM
Physics Building, Room 204
Note special room.

Nuclear/Particle Seminar

## "CLEO-c: A New Frontier of Weak and Strong Interactions"

Daniel Cronin-Hennessy , University of Minnesota
[Host: E. Craig Dukes]
ABSTRACT:
The Cornell Electron-positron Storage Ring (CESR) upgrade has provided a high luminosity dataset in the charm threshold region. Among the goals of the CLEO-c experiment are precision measurements of charm leptonic and semileptonic decay rates. These data are used to confront lattice-QCD predictions for hadronic decay constants and form factors. Validation of lattice-QCD will allow for improved CKM constraints. I will overview the goals of the CLEO-c ecxperiment and report recent progress.
High Energy Physics Seminar
Wednesday, February 21, 2007
3:30 PM
Physics Building, Room 204
Note special room.

## "Bulk Viscosity of High Temperature QCD"

Caglar Dogan , University of Virginia
[Host: E. Craig Dukes]
ABSTRACT:
The data obtained from RHIC experiments is reproduced pretty well by ideal hydrodynarnical models. However, the first corrections to perfect fluid behavior are also important in interpreting the data and are characterized by shear and bulk viscosities, I will explain the perturbative calculation of the bulk viscosity of high-temperature QCD using kinetic theory to leading order in the coupling constant. This fills a gap in the literature since even a parametric estimate of this quantity was absent prior to OUT work. Although it may not be justified to apply our results to the strongly coupled plasma produced at RHIC, we hope that they will at least provide the right order of magnitude.
High Energy Physics Seminar
Wednesday, January 31, 2007
3:30 PM
Physics Building, Room 204
Note special room.

## "Recent QCD Measurements at D-Zero"

Duncan Brown , University of Texas, Arlington
[Host: Bob Hirosky]
SLIDESHOW:
High Energy Physics Seminar
Wednesday, January 24, 2007
3:30 PM
Physics Building, Room 204
Note special room.

Slideshow (PDF)

## "Cabibbo Haze in Lepton Mixing"

Lisa Everett , Univeristy of Wisconsin
[Host: Peter Arnold]
High Energy Physics Seminar
Wednesday, January 17, 2007
3:30 PM
Physics Building, Room 204
Note special room.

## "N/A"

High Energy Physics Seminar
Wednesday, December 13, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "N/A"

Thanksgiving Recess , N/A
[Host: N/A]
High Energy Physics Seminar
Wednesday, November 22, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "IceCube: A Cubic Kilometer Neutrino Telescope"

Patrick Toale , Penn State
[Host: E. Craig Dukes]
ABSTRACT:
The IceCube neutrino telescope, located deep in the glacial ice at the geographic South Pole, is the worlds largest neutrino observatory. The primary goal of IceCube is the detection of high energy neutrinos of astrophysical origin. In its second year of construction, IceCube now includes its predecessor, AMANDA. This talk will cover the science goals, design, and construction of IceCube, along with recent results from AMANDA.
High Energy Physics Seminar
Wednesday, November 8, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "Worldline Instantons and Pair Production"

Qinghai Wang , Unversity of Connecticut
[Host: Paul Fendley]
ABSTRACT:
The imaginary part of the QED effective action can be approximated by the contribution of a worldline instanton, a solution to the classical Euclidean worldline equations of motion. In this talk, I will briefly review this formalism and compute also the prefactor arising from quantum fluctuations about this classical path. I will show the excellent agreement between our semiclassical approximation, conventional WKB, and numerical results using numerical worldline loops. I will also show the extension of the worldline instanton technique to multidimensional spatially inhomogeneous electric background fields, for which, WKB failed to apply.
High Energy Physics Seminar
Wednesday, October 25, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "The Dark Energy Survey"

Stefan Gruenendahl , Fermilab
[Host: E. Craig Dukes]
High Energy Physics Seminar
Thursday, October 12, 2006
4:00 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

## "Hadronic Particle Production and the Future of Neutrino Physics"

Andrew J. Norman , University of Virginia
[Host: E. Craig Dukes]
High Energy Physics Seminar
Wednesday, September 20, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "Small Instantons in CP1 and CP2 Sigma Models "

Yaogang Lian , UVA
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, May 3, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "Hairpin Diagrams and the Planar Equivalence of One-Flavor QCD and N=1 Supersymmetric Yang-Mills Theory"

Patrick Keith-Hynes , UVA
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, April 26, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "First MINOS Results from the NuMI Neutrino Beam"

Jeff Nelson , William & Mary
[Host: Craig Dukes]
ABSTRACT:
The Main Injector Neutrino Oscillation Search (MINOS) experiment recently completed its first year of exposure to the NuMI neutrino beam. In this run muon neutrinos produced at Fermilab near Chicago were directed 734.3km through the Earth to the 5,400 ton MINOS far detector located a half mile underground in the Soudan Underground Laboratory in northern Minnesota. This talk will describe the performance of the NuMI neutrino and the MINOS detectors during this initial run and will include presentation of preliminary data from this initial data run.
High Energy Physics Seminar
Wednesday, April 19, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "Models of Neutrino Masses in Extra Dimensions"

[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, April 12, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "Charm Physics from CLEO-c"

Roy Briere , Carnegie Mellon University
[Host: Dinko Počanić]
ABSTRACT:
The CLEO-c physics program includes studies of D(s) mesons and charmonium. Precision results are of interest for weak flavor physics, including verification of lattice QCD. Many results for D0 and D+ are already available, and Ds data taking has begun recently. Charmonium data and the energy scan used to find a Ds running point offer QCD and spectroscopy results as well. I will introduce the CLEO-c program, and illustrate its impact with a selection of recent results and future plans.
High Energy Physics Seminar
Wednesday, April 5, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "Accurate Lattice Calculations for Quark Flavor Physics"

Matthew Wingate , University of Washington
[Host: Hank Thacker]
ABSTRACT:
Lattice QCD calculations now include the effects of 2 light sea quarks and 1 strange sea quark through the use of an improved staggered fermion action; consequently, calculations important to quark flavor physics are free of the unsystematic errors that infected previous calculations. Furthermore, the work of the previous decade to reduce discretization errors, to tame lattice perturbation theory, to control light quark mass extrapolations, and to implement heavy lattice quarks is finally converging to yield realistic, accurate calculations. In this talk I discuss some important recent innovations we employ, show tests of the methodology, and present our current results. I conclude by showing the impact of the results on constraints of Standard Model parameters and by mapping the route for further improvement.
High Energy Physics Seminar
Wednesday, March 15, 2006
3:30 PM
Physics Building, Room 204
Note special room.

Joint Nuclear/High Energy Physics Seminar

## "TO BE ANNOUNCED"

RESERVED , UVA
[Host: JKG]
High Energy Physics Seminar
Wednesday, March 1, 2006
3:30 PM
Physics Building, Room 204
Note special room.

## "Axion Phenomenology"

Rodney Crewther , University of Adelaide
[Host: P.Q. Hung]
ABSTRACT:
The best explanation for the lack of CP violation by strong interactions involves the existence of axions: light, weakly interacting spin-0 particles. The PVLAS experiment, hep-ex/0507107, reports seeing a rotation of the polarization of 0.1 W laser light in a transverse magnetic field consistent with having an axion but with an extremely large (unlikely?) ratio of electromagnetic to color anomalies. JLab's FEL Axion group plans to use its 10 kW free-electron laser to provide a rigorous check on the PVLAS result and to look for photon regeneration due to propagating axions. I will review the reasons for having axions and explain why experiments of this type are so important.
High Energy Physics Seminar
Wednesday, February 1, 2006
3:30 PM
Physics Building, Room 204
Note special room.

Special High Energy Seminar

## "Chiral Effective-Field Theory in the Resonance Region"

Vladimir Pascalutsa , The College of William and Mary /Jefferson Lab - Theory Group
[Host: Cole Smith]
ABSTRACT:
I will discuss the chiral effective-field theory of QCD can be extended to the Delta-resonance energy region. This framework will then be applied to the pion electroproduction, radiative pion electroproduction, and Compton scattering with the aim of a model-independent study of the Delta-resonance properties. These results will be contrasted with the state-of-the-art lattice QCD studies.
High Energy Physics Seminar
Wednesday, January 18, 2006
3:30 PM
Physics Building, Room 204
Note special room.

This is a joint Nuclear-High Energy seminar

## "Using Exotic Pulsars to Probe Fundamental Physics"

Scott Ranson , NRAO
[Host: P.Q. Hung]
ABSTRACT:
Over the past several years, deep searches with the world's largest radio telescopes have uncovered several truly exotic pulsar systems. Observations of these objects using the incredibly precise techniques of pulsar timing, allow us to probe regimes of gravitational, electromagnetic, plasma, and particle physics that are impossible to reach in laboratories here on earth. In this talk I'll discuss several of the most interesting recent discoveries and show how they are onstraining gravitational theories, plasma physics, and the physics of matter at supranuclear densities.
High Energy Physics Seminar
Wednesday, November 30, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "208Pb Radius Experiment -- PREX"

Robert Michaels , Thomas Jefferson National Accelerator Facility, USA
[Host: Donal Day]
ABSTRACT:
The difference between the neutron radius Rn of a heavy nucleus and the proton radius Rp is believed to be several percent. This neutron skin has proven to be elusive to pin down experimentally in a rigorous fashion. The proposed Lead Radius Experiment PREX will measure the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 208Pb at an energy of 850 MeV and a scattering angle of 6 degrees. Since the Z0 boson couples mainly to neutrons, this asymmetry provides a clean measurement of Rn with a projected experimental precision of Â±1%. In addition to being a fundamental test of nuclear theory, a precise measurement of Rn pins down the density dependence of the symmetry energy of neutron rich nuclear matter which has impacts on neutron star structure and atomic parity violation experiments.
High Energy Physics Seminar
Wednesday, November 16, 2005
3:30 PM
Physics Building, Room 204
Note special room.

Joint Nuclear/High Energy Seminar

## "Recent B Physics Result from CDF"

Manfred Paulini , Carnegie Mellon University
[Host: Craig Dukes]
ABSTRACT:
We discuss selected heavy flavour physics results from the Collider Detector at Fermilab (CDF) operating at the Run II Tevatron Collider at Fermilab. We focus on the search for particle-antiparticle oscillations in the system of neutral Bs0 mesons which is one of the high priority analyses of the CDF B physics program in Run II.
High Energy Physics Seminar
Wednesday, October 12, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "Status of the CMS Experiment"

Drew Baden , University of Maryland
[Host: Robert Hirosky]
High Energy Physics Seminar
Wednesday, May 4, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "Study of CP(N) Models"

[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, April 27, 2005
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Neutrino Oscillations and the MINOS Experiment"

Nathanial Tagg , Oxford University
[Host: Craig Dukes]
ABSTRACT:
Neutrinos have started to gain enormous attention over the last 30 years because of strange properties that allow them to seemingly disappear when travelling long distances. I will give brief history of the important discoveries by neutrino experiments to put the newly-started MINOS experiment into context. MINOS is an experiment to produce neutrinos at Fermilab (near Chicago) and fire them undgeround to the Soudan lab (near Duluth), a baseline of 730km. The challenges of performing this long-baseline neutrino oscillation experiment will be discussed.
High Energy Physics Seminar
Thursday, April 14, 2005
2:30 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

*Please note special date, time, and location.

## "Searching for Neutrino Oscillations: Early Results from MiniBooNE"

Bill Louis , LANL
[Host: P.Q. Hung]
ABSTRACT:
The MiniBooNE experiment at Fermilab is designed to be a definitive test of the LSND evidence for neutrino oscillations. If the LSND evidence is confirmed, then, together with the results from solar, reactor, and atmospheric neutrino oscillation experiments, it would imply Physics Beyond the Standard Model, such as sterile neutrinos, CPT/Lorentz violation, or mass-varying neutrinos. After two and a half years of operation, MiniBooNE has collected about 500K neutrino events and is clearly observing charged-current quasi-elastic events, charged-current pion events, neutral-current pi0 events, and neutral-current elastic events. Some of these early, non-oscillation physics results will be presented along with the prospects for the future.
High Energy Physics Seminar
Wednesday, April 6, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "HAPPEX: Looking for Strange Quark Structure in the Nucleon"

Tim Holmstron
[Host: Craig Dukes]
High Energy Physics Seminar
Wednesday, March 30, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "Leptogenesis with Massive Neutrinos Abstract"

E. Paschos , University of Dortmund, Germany
ABSTRACT:
Leptogenesis provides an attractive first step for creating the Baryon Asymmetry in the Universe. The couplings of heavy Neutrinos contain, in general, Dirac and Majorana mass terms which break the CP symmetry. Their decays produce a lepton asymmetry which subsequently is converted into a baryon asymmetry. Models with this property and their implications for neutrino experiments and structure formation in the universe will be discussed.
High Energy Physics Seminar
Wednesday, March 23, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "Plan Polarizability and Chiral Effective Theory"

Chung-Wen Kau , NCSU
[Host: Blaine Norum]
High Energy Physics Seminar
Wednesday, March 9, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "The Search for KL-> 2&pi 0&gamma"

David Smith , UVA
ABSTRACT:
The decay KL-> 2π 0γ is interesting as a probe of the sixth order of chiral perturbation theory. I am currently searching for this decay using data collected by the KTeV experiment in 1997. The decay is swamped by 3π0background events with one missing photon. Using Monte Carlo simulations of the two modes, I have designed cuts to eliminate this background while retaining signal events. The current upper limit on the decay is 5.6*10-6; my current single event sensitivity is 2.19*10-7 with only one background event remaining for one flux of data. I hope to extend this work to the 1999 data while retaining this low SES and background level.
High Energy Physics Seminar
Wednesday, March 2, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "TBA"

AVAILABLE
High Energy Physics Seminar
Wednesday, February 23, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "TBA"

AVAILABLE
High Energy Physics Seminar
Wednesday, February 16, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "TBA"

AVAILABLE
High Energy Physics Seminar
Wednesday, February 9, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "TBA"

AVAILABLE
High Energy Physics Seminar
Wednesday, February 2, 2005
3:30 PM
Physics Building, Room 204
Note special room.

## "**TBA**"

***RESERVED**
High Energy Physics Seminar
Wednesday, January 26, 2005
3:30 PM
Physics Building, Room 204
Note special room.

See Suzie Garrett

## "Status of Nuclear Physics and High Energy Research in Vietnam"

Vo Van Thuan , Institute for Nuclear Science and Technology, Hanoi
[Host: P. Q. Hung]
High Energy Physics Seminar
Wednesday, January 19, 2005
2:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "3D Parton Imaging of the Nucleon in High Energy pp and pA Collisions"

Christian Weiss , Jefferson Laboratory
[Host: Simonetta Liuti]
High Energy Physics Seminar
Wednesday, December 8, 2004
3:30 PM
Physics Building, Room 204
Note special room.

Joint with High Energy/Nuclear

## "Recent Results From KLOE at DAFNE"

Matteo Palutan , Laboratori Nazionali di Frascati
[Host: Sergio Conetti]
ABSTRACT:
Recent results obtained by the KLOE experiment at the phi-factory DAFNE will be presented. They mainly concern neutral kaon physics including rare K_S decays, K_L lifetime and branching ratio's; a comprehensive discussion of the measurements that bear on the extraction of Vus will be given. The study of scalar and pseudoscalar meson production in radiative phi decays and the measurement of the e+e- hadronic cross section using the initial state radiation will also be reviewed.
High Energy Physics Seminar
Thursday, December 2, 2004
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "The Decay Σ+ → pÂµ+Âµ- and Possible New Physics from HyperCP"

HyangKyu Park , University of Michigan
[Host: Hank Thacker]
ABSTRACT:
The Fermilab HyperCP (E871) experiment collected on the order of 1010 hyperon decays in 1997 and 1999 runs. Using the entire data set, we will report on the observation of events with reconstructed masses consistent with that of Σ+ assuming the final state pÂµ+Âµ-. The observed events would be the rarest decay ever observed in the baryon sector. Possible interpretations of the observed events will be discussed. Finally we will present a speculation for a new physics scenario.
High Energy Physics Seminar
Wednesday, November 3, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "Gross-Witten Point and Deconfinement in Matrix Models"

Rob Pisarski , Brookhaven National Lab
[Host: Hank Thacker]
High Energy Physics Seminar
Friday, October 29, 2004
12:00 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

## "A High Statistics Search for the Theta-plus Pentaquark"

Mike Longo , University of Michigan
[Host: Craig Dukes]
ABSTRACT:
There have been many reported sightings of exotic strange five-quark baryons in the past two years. Using the HyperCP dataset, which includes the largest K-short sample ever taken, we have searched for Theta-plus(1.54) -> K-zero + proton decays, with a spectrometer with excellent mass resolution.
High Energy Physics Seminar
Wednesday, October 20, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "A Neural Network Analysis of the Top Cross Section at CDF"

[Host: Bob Hirosky]
High Energy Physics Seminar
Wednesday, October 13, 2004
10:00 AM
HEP Conference Room, Room 123
Note special time.
Note special room.

## "Lambda_c and Lambda_b Measurements From FOCUS and D0"

Abaz Kryemadhi , University of Indiana
[Host: Bob Hirosky]
High Energy Physics Seminar
Tuesday, October 12, 2004
1:30 PM
HEP Conference Room, Room 123
Note special date.
Note special time.
Note special room.

## "Beautiful B Physics at DO"

Rick Jesik , Imperial College, London
[Host: Bob Hirosky]
High Energy Physics Seminar
Wednesday, September 29, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "Hadron Structure from Lattice QCD"

David Richards , J Lab
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, September 22, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "Some Old Puzzles of Particle Physics and Cosmology in the Light of the the Two Measures Theory"

Alexander Kaganovich , Ben Gurion University
[Host: P.Q. Hung]
High Energy Physics Seminar
Wednesday, September 15, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "The MECO Experiment to Search for Mu N- ---> e- N with 10-17 Sensitivity"

Bill Molzon's , University of California at Irvine
[Host: Craig Dukes]
ABSTRACT:
The Muon to Electron Conversion (MECO) experiment is designed to detect the coherent conversion of muons to electrons in the field of a nucleus if this process occurs as infrequently as once for 10-17 muons that are captured in a muonic atom. To date, no examples of muon and electron number violating transitions have been seen in charged lepton processes, and MECO will improve the sensitivity of past searches by 3-4 orders of magnitude. MECO has sufficient sensitivity to discover this muon-number violating process if it occurs at rates predicted in several well-motivated models for physics beyond the Standard Model, e.g. a broad class of grand-unified supersymmetric models. I will briefly discuss the motivation for and status of searches for lepton flavor violating (LFV) processes and the status of other experiments under construction, and then describe the MECO experiment. I will concentrate on recent progress on some technical aspects of the experiment and present the prospects for its construction and operation.
High Energy Physics Seminar
Friday, May 21, 2004
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Effective Interactions are Effective Interactions"

Barry Holstein , University of Massachusetts
[Host: Hank Thacker]
ABSTRACT:
The use of effective field theory techniques will be discussed and applications given in classical and quantum mechanics, in condensed matter physics, in QCD, and in quantum gravity.
High Energy Physics Seminar
Wednesday, April 28, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "To the Frontiers of HighField/High Energy Density Physics and Ultrafast Processes via Energy Recovering Linacs"

[Host: Blaine Norum]
High Energy Physics Seminar
Wednesday, April 21, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "Search For New Direct CP Violation in Neutral Kaon Decays"

Michael Ronquest , UVA
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, April 7, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "Many New Faces of Extradimension Theory"

Ngoc-Khanh Tran , UVA
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, March 24, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "Deconstruction and the Cosmological Constant"

V. Jejjala , Virginia Tech
[Host: Paul Fendley]
High Energy Physics Seminar
Wednesday, January 21, 2004
3:30 PM
Physics Building, Room 204
Note special room.

## "Collective Modes of an Anisotropic QGP"

Mike Strickland , Techische Universitat , Vienna
[Host: Peter Arnold]
ABSTRACT:
In this talk I will discuss the collective modes of a quark-gluon plasma which has a momentum-space anisotropy in the quark and/or gluon districution functions. I will derive the hard thermal loop gluon self-energies using classical kinetic theory for anistropic systems and show that in addition to the normal stable aluonic quasiparticle modes there exist also unstable gluonic quasiparticle modes which can affect the thermalization and isotropization of a quark-gluon plasma. I will then demonstrate how the anisotropic HTL gluonic self-energy can be used to calculate the directional dependence of the heavy quark energy loss in an anisotropic QGP. Along the way I will also talk a bit about the isotopic limit and demonstrate that the heavy quark energy loss obtained is never negative.
High Energy Physics Seminar
Monday, January 5, 2004
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

## "Precision Measurement of the Weak Mixing Angle in Parity-Violating Moller Scattering"

Imran Younus , Syracuse University
[Host: Craig Dukes]
ABSTRACT:
SLAC E158 is an experiment to measure the parity non-conserving asymmetry in Moller scattering. Longitudinally polarized 48 GeV electrons are scattered off unpolarized (atomic) electrons in a liquid hydrogen target with an average Q2 of 0.027 GeV2. The asymmetry in this process is proportional to the weak mixing angle. The preliminary results give APV = â151.9 +/â 29.0(stat) +/â 32.5(syst) parts per billion. For the sine of the weak mixing angle 0.2371 +/â 0.0025 +/â 0.0027, which is consistent with the Standard Model prediction (0.2386 +/â 0.0006).
High Energy Physics Seminar
Wednesday, November 12, 2003
4:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Measurement of the Branching Fraction for K-long -> mu+ mu- e+ e-"

Andrew Norman , College of William and Mary
[Host: Craig Dukes]
ABSTRACT:
This seminar will describe the measurement of decay of the long lived neutral kaon into two muons and two electrons. The measurement was performed using the data taken during experiment E871 which ws performed on the B5 beamline at the Alternating Gradient Synchrotron (AGS) of the Brookhaven National Laboratory (BNL).(For a complete abstract, please see posted announcement in the Physics Bldg. )
High Energy Physics Seminar
Wednesday, October 22, 2003
3:30 PM
Physics Building, Room 204
Note special room.

## "Elitzur's theorem and the sign problem"

Kim Splittorff , State University of New York, Stony Brook
ABSTRACT:
Elitzur's theorem stating the impossibility of spontaneous breaking of local symmetries in a gauge theory is reexamined. The existing proofs of this theorem rely on gauge invariance as well as positivity of the weight in the Euclidean partition function. We examine the validity of Elitzur's theorem in gauge theories for which the Euclidean measure of the partition function is not positive definite. We find that Elitzur's theorem does not follow from gauge invariance alone. We formulate a general criterion under which spontaneous breaking of local symmetries in a gauge theory is excluded. Finally we illustrate the results in an exactly solvable two dimensional abelian gauge theory.
High Energy Physics Seminar
Monday, August 18, 2003
3:00 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

SPECIAL HIGH ENERGY SEMINAR. Please note day and time!!

## "FINeSE: Fermilab Intense Neutrino Scattering Experiment"

Dr. Bonnie Fleming , FermiLab
[Host: Lanchun Lu]
ABSTRACT:
The Booster neutrino beamline at Fermilab provides the world's highest intensity neutrino beam in the 0.5-1.0 GeV energy range. There is a wealth of neutrino physics that can be accomplished using this beam in addition to the oscillation physics already underway. A 10 ton detector located at 100 meters from the recently commissioned Booster neutrino source would definitively measure the strange quark contribution to the nucleon spin. In addition, it would also complement the existing MiniBooNE oscillation experimental program by, along with MiniBooNE data, making an improved measurement of the search for muon neutrino disappearance in a region of particular interest to cosmologists. FINeSE will also be able to investigate neutrino-scattering cross sections at low energy, in a region where there is growing interest in neutrino scattering interactions. This physics program and the FINeSE detector will be presented.
High Energy Physics Seminar
Wednesday, May 7, 2003
4:00 PM
Physics Building, Room 313
Note special time.
Note special room.

Please note special room and time

## "Viewing the nucleon through "color" filters"

Prof. Xiangdong Ji , Univ. of Maryland
[Host: Xiaotong Song]
ABSTRACT:
While the form factors and parton distributions provide separately the shape of the proton in coordinate and momentum spaces, a more powerful imaging of the proton structure can be obtained through phase-space distributions. In this talk, I introduce the Wigner-type quark and gluon distributions which depict a full-3D proton at every fixed light-cone momentum, like what is seen through momentum ("color")-filters. After appropriate phase-space reductions, the Wigner distributions are related to the generalized parton distributions (GPD's) and transverse-momentum dependent parton distributions, which are measurable in high-energy experiments. The new interpretation of GPD's provides a classical way to visualize the orbital motion of the quarks, which is known to be the key to the spin and magnetic moment of the proton.
High Energy Physics Seminar
Wednesday, April 16, 2003
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

Special Nuclear and High Energy

## "Photon emission from dense quark matter in compact stars"

Carston Vogt , Nordita
[Host: J. Lenaghan]
ABSTRACT:
Quark matter at large baryon density is characterised by a colour-flavour-locked phase where chiral symmetry is broken. This leads to the appearance of the light octet of Goldstone bosons. At temperatures below the gap which results from quark pairing, the light Goldstone bosons are the dominant degrees of freedom and provide the main source for photon emission. We calculate photon emission rates from scattering of Goldstone bosons and discuss possible observational consequences of our results for compact stars featuring colour-superconductivity.
High Energy Physics Seminar
Wednesday, April 9, 2003
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Phenomenology of a mass matrix from six dimensions"

Andrea Soddu , UVA
[Host: P. Q. Hung]
ABSTRACT:
A model with two compactified extra spatial dimensions is introduced. A mass matrix with democratic structure, a common Yukawa coupling for the three families and all the matrix elements of the same order of magnitude, is derived. The mass spectrum and CKM matrix obtained in a ten parameter version of the model will be presented together with a possible scenario which could solve the Strong CP problem without axions.
High Energy Physics Seminar
Wednesday, April 2, 2003
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Developments in time evolution"

Thomas Curtwright , University of Miami
[Host: Hank Thacker]
ABSTRACT:
Properties of quantum Nambu-brackets are studied in various physical situations. The brackets are shown to define time evolution in ways that can be quite novel, perhaps even very unusual, but which are nonetheless always fully consistent. The key physical ideas are to use different time scales on different invariant sectors of a system, and to conjoin time evolution with symmetries of the system's dynamics. For finite times, this formulation of time-development is not the usual unitary transformation, but nonetheless it gives results from which conventional, unitarily evolved data can be recovered. The methods are applicable to quantum field theory, perhaps the physical deas more generally than the Nambu brackets.
High Energy Physics Seminar
Wednesday, March 26, 2003
3:30 PM
Physics Building, Room 204
Note special room.

## "Transport coefficients in hot field theory"

Gert Aarts , Ohio State University
[Host: Peter Arnold]
High Energy Physics Seminar
Wednesday, March 19, 2003
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Running with the Radius in RS1"

[Host: Donal Day]
ABSTRACT:
We find a renormalization group formalism in the compactified Randall-Sundrum scenario with the renormalization scale set by the radius of the compact space. Couplings on the hidden brane run with the size of the space. We use this formalism to demonstrate the stability of the hierarchy.
High Energy Physics Seminar
Wednesday, February 19, 2003
3:30 PM
Physics Building, Room 204
Note special room.

## "Panning for Gold (or Finding your physics in a torrent of data)"

Prof. Robert Hirosky , UVA
ABSTRACT:
Interesting physics interactions occur copiously at high energy hadron colliders. However, these events are often swamped by background interactions with rates many orders of magnitude greater. Further, bandwidth and storage constraints require O(10^5-10^6) or greater real time data rejection for collecting data samples. This talk will review the 'Trigger' or real time data selection strategies used in the D-Zero experiment at Fermilab and review the "golden" physics channels sought in the Run 2 collider program.
High Energy Physics Seminar
Wednesday, February 5, 2003
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Mesoscopic QCD and the Theta-Vacua"

Jonathan Lenaghan , UVA
[Host: H. Thacker]
ABSTRACT:
The partition functions of gauge theories with spontaneously broken chiral symmetries are analyzed for an arbitrary number of flavors, N_f, and arbitrary quark masses including the contributions from all topological sectors in the Leutwyler--Smilga regime. In the Leutwyler--Smilga regime, the theories only depend on simple combinations of quark masses, volume, chiral condensate and vacuum angle. We consider the cases of quarks in the adjoint and fundamental representation separately. For two and three flavors, the heta dependence of the QCD vacuum is studied in detail. We find a discontinuity at heta=pi in the first derivative of the energy density with respect to heta for degenerate quark masses. This corresponds to the first--order phase transition in which CP is spontaneously broken, known as Dashen's phenomena. We derive simple expressions for the chiral condensate and the topological density and show that they are in fact related. By examining the zeros of the various partition functions, we elucidate the mechanism leading to Dashen's phenomena in QCD.
High Energy Physics Seminar
Wednesday, December 4, 2002
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Holographic Renormalization Group, Time and String Theory"

Djordje Minic , Virginia Tech
[Host: Paul Fendley]
High Energy Physics Seminar
Wednesday, October 9, 2002
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "The CKM Experiment at Fermilab: Attacking the CKM Matrix Using Charged Kaons"

Craig Dukes , University of Virginia
[Host: H. Thacker]
ABSTRACT:
The CKM (Charged Kaons at the Main injector) collaboration is planning a new Fermilab experiment whose goal is to measure the Cabibbo, Kobayashi, Maskawa matrix element V(td) with a statistical precision of 5%. This is done through the measurement of the branching ratio of the ultra-rare charged kaon decay: K+ -> pi+ nu nu. This measurement will play a critical role in testing the Standard Model hypothesis that the sole source of CP violation in nature resides in the imaginary parts of the Cabibbo, Kobayashi, Maskawa matrix elements. Attacking this question in the kaon sector is both experimentally and theoretically independent of the ongoing programs to measure these same parameters in the B meson sector. To make this challenging measurement a novel decay-in-flight spectrometer has been designed. I will discuss the physics, the spectrometer, and give the status of the experiment.
High Energy Physics Seminar
Wednesday, May 1, 2002
3:30 PM
Physics Building, Room 204
Note special room.

## "Quantum mechanics on noncommutative Riemann surfaces"

Bogdan Morariu , Rockefeller University
[Host: Paul Fendley]
High Energy Physics Seminar
Wednesday, April 17, 2002
3:30 PM
Physics Building, Room 204
Note special room.

## "Zeroes of the neutrino mass matrix"

Paul Frampton , University of North Carolina, Chapel Hill
[Host: P. Q. Hung]
High Energy Physics Seminar
Wednesday, April 10, 2002
3:30 PM
Physics Building, Room 204
Note special room.

## "Melting the Color Glass Condensate in Heavy Ions Collisions"

Raju Venugopalan , Brookhaven National laboratory
[Host: S. Liuti]
High Energy Physics Seminar
Wednesday, November 7, 2001
12:45 PM
Physics Building, Room 313
Note special time.
Note special room.

Joint Nuclear/High Energy

## "Electroweak Breaking from the Bulk of Extra Dimensions"

Antonio Delgado , Johns Hopkins University
[Host: Marcos-Seco]
High Energy Physics Seminar
Wednesday, October 31, 2001
12:45 PM
Physics Building, Room 313
Note special time.
Note special room.

## "Absolute neutrino mass determination"

Heinrick Paes , Vanderbilt University
[Host: P. Q. Hung]
High Energy Physics Seminar
Friday, August 17, 2001
2:00 PM
Physics Building, Room 313
Note special date.
Note special time.
Note special room.

## "A local Langevin equation for slow long distance modes in hot Yang-Mills"

Deitrich Bodeker , Brookhaven National Laboratory
[Host: Peter Arnold]
High Energy Physics Seminar
Wednesday, May 16, 2001
3:30 PM
Physics Building, Room 204
Note special room.

## "Monte Carlo Simulation of Phase Transition in 3D O(N) Phi-4 theory"

Xuepeng Sun , UVA
High Energy Physics Seminar
Wednesday, May 2, 2001
3:30 PM
Physics Building, Room 204
Note special room.

## "A Measurement of the (D+ --> K-bar*0 l+ nul) (D+ --> K-bar0 l+ nul) Branching Fractions"

Sang-Joon Lee , University of Minnesota
[Host: Harry Thacker]
High Energy Physics Seminar
Thursday, April 26, 2001
4:00 PM
Physics Building, Room 204
Note special date.
Note special time.
Note special room.

Special High Energy Seminar

## "Physics of Decay KL --> pi+pi-e+e- at kTeV"

Alexander Golossanov , UVA - High Energy Physics
[Host: H. Thacker]
High Energy Physics Seminar
Wednesday, April 25, 2001
3:30 PM
Physics Building, Room 204
Note special room.

## "The phase transition temperature of relativistic phi-4 theory"

Svyatoslav Tkachenko , University of Virginia - Department of Physics
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, April 18, 2001
3:30 PM
Physics Building, Room 204
Note special room.

## "Physics of KL --> pi+pi- gamma at Ktev"

John Shields , UVA-High Energy Physics
High Energy Physics Seminar
Wednesday, April 11, 2001
3:30 PM
Physics Building, Room 204
Note special room.

## "Gravitational Radiation from Accreting Neutron Stars: Implications for Millisecond Pulsar Formation and LIGO"

Lars Bildsten , ITP, Santa Barbara
[Host: P. Q. Hung]
High Energy Physics Seminar
Wednesday, February 21, 2001
3:30 PM
Physics Building, Room 204
Note special room.

Special Physics/Astronomy

## "Baryogenesis in the MSSM"

Marcos Seco-Miquelez , UVA - Department of Physics
[Host: H. Thacker]
High Energy Physics Seminar
Wednesday, November 29, 2000
3:30 PM
Physics Building, Room 204
Note special room.

## "Measuring CP violation in Hyperons"

Tim Holmstrom , University of Virginia
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, November 15, 2000
3:30 PM
Physics Building, Room 204
Note special room.

## "High Power EUV Radiation Sources for Lithography"

Robert Rossmanith , Forschungszentrum Karlsruhe
[Host: Blaine Norum ]
High Energy Physics Seminar
Wednesday, October 4, 2000
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Reordering the Chiral Expansion - Solution of the Old Puzzle"

Martin Mojzis , Comunius University, Bratislava
[Host: Ivan Horvath]
High Energy Physics Seminar
Wednesday, August 2, 2000
3:00 PM
Physics Building, Room 313*
Note special time.
Note special room.

## "Present Status of LHCb An Experiment to Make Precision Studies of CP Violation in Beauty Hadron Decays"

Professor Tatsuya Nakada , CERN and Paul Scherrer Institute
High Energy Physics Seminar
Monday, June 12, 2000
3:00 PM
Physics Building, Room 204
Note special date.
Note special time.
Note special room.

## "Dynamically Broken Topcolor - Building Higgs Bosons without Other Higgs Bosons"

Howard Georgi , Harvard University
[Host: P. Q. Hung]
High Energy Physics Seminar
Friday, April 28, 2000
2:00 PM
Physics Building, Room 203
Note special date.
Note special time.
Note special room.

SPECIAL HIGH ENERGY SEMINAR

## "An Update on Nucleon Spin Structure Measurements at HERMES"

Geoffrey Court , University of Liverpool
[Host: Donald Crabb]
High Energy Physics Seminar
Wednesday, March 22, 2000
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

Joint Nuclear/High Energy

## "QCD and Dark Matter"

Prof. Sibaji Raha , Bose Institute, Calcutta and Brookhaven National laboratory, Upton, NY
[Host: P. K. Kabir]
High Energy Physics Seminar
Thursday, March 9, 2000
3:30 PM
Physics Building, Room 204
Note special date.
Note special room.

Special Nuclear/HEP Seminar

## "Recent Results from the NA48 Kaon Decay Experiment at CERN"

Professor Konrad Kleinknecht , Johannes Gutenberg University, Mainz, Germany
ABSTRACT:
The origin of the violation of CP (particle-antiparticle) symmetry in decays of neutral K mesons has been unclear for a long time after its discovery. The question is whether this violation is due to a new superweak interaction or to a small part of the well-known weak interaction. An experiment at CERN in 1988 (NA31) indicated that epsilon', the parameter that distinguishes between the two possibilities, is different from zero, thus pointing to the latter possibility, while an experiment at FNAL found a result consistent with zero. NA48 has measured the parameter epsilon'/epsilon of direct CP violation and confirms the earlier observation of NA31. Results will be given, as well as some results on rare Kaon decays. Postcript: This result was announced for the first time on March 7th at CERN. This will be the first North American discussion of this crucial measurement which points to the origin of CP (time reversal) violation.
High Energy Physics Seminar
Wednesday, March 8, 2000
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Chiral Symmetry and Long Wavelength Dirac Eigenmodes in QCD"

John McCune , University of Virginia
[Host: Hank Thacker]
High Energy Physics Seminar
Wednesday, March 1, 2000
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Effective and Ineffective Field Theory in Nuclear Physics"

Tom Cohen , University of Maryland
[Host: J.V. Noble]
High Energy Physics Seminar
Wednesday, February 23, 2000
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

Joint Nuclear - High Energy Seminar

## "Supersymmetry Breaking in SO(10) models"

Pedro Mercadente , Florida State University
[Host: P. Q. Hung]
High Energy Physics Seminar
Thursday, February 17, 2000
4:00 PM
Physics Building, Room 204
Note special date.
Note special time.
Note special room.

Special High Energy Seminar

## "Efferctive theories of electroweak baryon number violation"

Peter Arnold , University of Virginia
High Energy Physics Seminar
Wednesday, February 16, 2000
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "The Angular Momentum Sum-Rule - - - Spin-Doctoring the Proton"

Ben White , University of Swansea
[Host: P. Q. Hung]
High Energy Physics Seminar
Wednesday, February 16, 2000
4:15 PM
Physics Building, Room 204
Note special time.
Note special room.

Special High Energy Seminar

## "Excited Baryons in Large Nc QCD"

Carl Carlson , College of William and Mary
High Energy Physics Seminar
Wednesday, December 8, 1999
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Non-forward Parton Distribution and Deeply Virtual Compton Scattering"

Igor Musatov , Old Dominion University
High Energy Physics Seminar
Wednesday, December 1, 1999
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

## "Quark-Hadron Duality - Recent results from Jefferson Lab"

Cynthia Keppel , Hampton University / Jefferson Lab
[Host: S. Luiti]
High Energy Physics Seminar
Wednesday, November 17, 1999
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.

Joint Nuclear/High Energy

## "Weak Matrix Elements in the Large Nc expansion of QCD "

Bill Bardeen , Fermilab
[Host: Thacker/Horvath]
High Energy Physics Seminar
Wednesday, October 20, 1999
3:00 PM
Physics Building, Room 204
Note special time.
Note special room.