High Energy Physics Seminars History

Searches for long-lived particles (LLPs) with macroscopic decay lengths are a rapidly expanding frontier at the LHC and other collider experiments. Still, many gaps remain in the current search program, in particular for light LLPs with masses at the GeV or sub-GeV scale and with decay lengths on the order of meters. In this talk, I will illustrate approaches to filling this gap by discussing two models of light LLPs that naturally fall into this decay length regime and their signals at the LHC and at Belle II. First, I will discuss a theory with a heavy vectorlike lepton that decays into pseudoscalar and a tau lepton, and focus on signals of long-lived pseudoscalars in the muon chambers of CMS or ATLAS. Second, I will illustrate the sensitivity of Belle II to light LLPs with meter-scale decay lengths using displaced vertex signals from strongly interacting dark sectors as an example.

Higgs bosons produced at high momentum are rare, but measurable. The tails of their kinetic spectrum can provide a unique insight on whether anomalous interactions exist at the TeV scale. The production of Higgs boson pairs is even rarer - about 1000 times less frequent- but it can be enhanced in some new physics models, particularly when the pairs are produced at high momentum. This talk reviews how final states with jets have enabled the exploration of these elusive and possibly anomalous couplings, even in a difficult collider environment that is full of quarks and gluons like the Large Hadron Collider. We examine advances on particle jet identification that have drastically improved our ability to identify boosted Higgs and increased our physics reach. Finally, I will talk about how calorimetry detectors need more spatial precision, greater radiation tolerance, and smarter readout electronics to ensure that this and other search programs can continue at the upcoming High-Luminosity LHC run.

The CMS experiment at CERN will be significantly upgraded during Long Shutdown 3 of the LHC (2026-2028) to operate with a 10-fold increase in luminosity and the associated event pileup of 140-200 proton-proton interactions per bunch crossing of the High-Luminosity LHC (HL-LHC).  The endcap calorimeter region, covering 1.5 < |η| < 3.0, will be exposed to very high radiation levels and to mitigate this, a new calorimeter, the High Granularity Calorimeter (CE), will replace the existing endcap calorimeter.  It will have higher transverse and longitudinal segmentation for both electromagnetic (CE-E) and hadronic (CE-H) sections to facilitate particle-flow reconstruction.  The fine structure of showers can be measured and used to enhance particle identification, whilst still achieving good energy resolution.  The CE-E, and a large fraction of CE-H, will use hexagonal silicon sensors produced from 8-inch wafers as active material, each with several hundreds of individual cells of 0.5-1 sq. cm cell size.  The remainder of the CE-H will use highly-segmented scintillators read out with SiPMs as active material.  An overview of the CE project, including motivation, design, timeline, and expected performance, will be presented in this talk together with a deeper look at the silicon sensor design and performance status on the eve of pre-production.

The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for a thermal origin of dark matter sharpen this mass range to within about an MeV to 100 TeV. Most of the stable constituents of known matter have masses in the MeV to GeV range, and a thermal origin for dark matter works in a simple and predictive manner in this mass range as well, yet it remains largely unexplored. The Heavy Photon Search (HPS) at Jefferson Lab is a fixed target experiment that uses an electron beam to probe models of thermal dark matter involving sub-GeV dark photons. HPS searches for visibly decaying dark photons through two distinct methods - a resonance search in the e+e- invariant mass distribution and a displaced vertex search for long-lived dark photons. This seminar will give an overview of the theoretical motivations, the main experimental challenges and how they are addressed, the results for the 2016 Engineering Run, and future data and upgrades. In addition, an introduction to the Light Dark Matter eXperiment (LDMX), a planned next generation experiment at SLAC that will search for invisibly decaying dark photons through a missing-momentum experiment, will be presented.

Monte Carlo Event Generators are essential for the analysis and interpretation of Collider data. Event generation starts at energies of several hundred GeV with the hard interaction between quarks and gluons and ends at the scale of several hundred MeV with hadrons, leptons and photons as the final products. This energy gap is bridged by parton shower algorithms, which evolve the products of the hard interaction down to the hadronization scale. In this talk I will discuss recent improvements on the formal accuracy of parton showers and the performance of phase-space integrators, both crucial ingredients for precision physics at the HL-LHC.

The axion is a hypothetical particle that may solve two problems in particle physics & cosmology, the Strong-CP problem and the nature of dark matter. The Axion Dark Matter Experiment (ADMX) is the DOE Flagship search for these particles as part of the “Generation-2” direct dark matter search program in High Energy Physics. The experiment uses a tunable resonant cavity in a large static magnetic field to enhance the conversion of axions to detectable microwaves. Quantum-limited amplifiers based on superconducting Josephson Junction circuits are critical to allow the search to be sensitive enough to rapidly scan the frequencies where the axion may exist.  Here I will describe the status of the search along with an update on the planning and prototyping for the next phase of ADMX.”

Despite the successes of the Standard Model of particle physics, it remains a challenge to understand the dynamics of the strong interaction among the building blocks of hadronic matter, namely quarks and gluons. At small distance scales or at high energies, the underlying theory, the Quantum Chromodynamics (QCD), is well tested and understood. Our understanding of the strong interaction deteriorates dramatically at larger distances scales such as the size of the nucleon. This so-called "strong QCD regime” exhibits spectacular effects such as the generation of hadron masses and color confinement. Moreover, the nature of QCD implies the existence of gluon-rich hadrons, such as glueballs and hybrids, multi-quark states, and molecules. This presentation will highlight a future research program that aims to provide precision data exploiting collisions of an intense beam of cooled anti-protons with protons or nuclei. This experiment, called PANDA at FAIR, has the ambition to carry out comprehensive spectroscopy studies of hadrons in the strange, charm, and gluon-rich regimes, covering topics in the field of nuclear, hadron, and particle physics.

The Standard Model of particle physics has been a crowning achievement of fundamental physics, culminating in the discovery of the Higgs boson in 2012. As a quantum theory of the building blocks of matter and forces, it has been one of the most successful theories in science. The recent measurement of the mass of the W boson disagrees with the theory prediction. This upset to the Standard Model may point towards exciting new discoveries in particle physics in the coming years. We will discuss the Standard Model, the crucial role of the W boson, and how it has become the harbinger of new laws of nature.

The discovery of coherent elastic neutrino-nucleus scattering (CEvNS) was made by the COHERENT Collaboration in 2017 using a CsI[Na] scintillating crystal at Oak Ridge National Laboratory's Spallation Neutron Source (SNS). This observation was made over 40 years after the theoretical prediction by Freedman et al. and consists of a neutral-current neutrino-nucleus interaction on an entire nucleus as a whole. The CEvNS process is the dominant scattering mode below 100 MeV and serves as a fertile testbed for precisely examining the Standard Model and has applications in nuclear reactor monitoring and stellar astrophysics. COHERENT built out the CEvNS physics program to include detector systems using liquid argon (CENNS-10), germanium (GeMini) and NaI[Tl] crystals (NaIvEte)--of which liquid argon successfully yielded an additional CEvNS measurement. The variety of media studied within the COHERENT detector suite works towards establishing the predicted N^2 dependence of the CEvNS cross section. Additionally, the COHERENT Collaboration houses several detector systems aimed at elucidating inelastic neutrino-nucleus interactions in support of CEvNS searches and as standalone investigates of neutrino-induced nuclear reactions. This presentation will consist of both the published results and the ongoing work being done on new detectors to further advance the physics goals of the collaboration. 

The nature of dark matter poses one of the most pressing questions in fundamental physics today. Thermal freeze-out of a weakly interacting massive particle (WIMP) has proved to be a successful framework for explaining the measured dark matter abundance in the Universe. However, the sizeable couplings of dark matter to the Standard Model particles required in its simplest realizations have been put under severe pressure by experimental null-results at colliders, direct and indirect detection experiments. Hence, fulfilling the relic density constraint often requires the exploration of ‘exceptional’ regions, e.g. the region where coannihilation effects increase the effective annihilation rate. In this talk, we revisit the assumptions commonly made within the coannihilation scenario and discuss a new variant of dark matter freeze-out, dubbed conversion-driven freeze-out (or coscattering). In this scenario, the relic abundance is set by the freeze-out of conversion processes requiring significantly smaller couplings of dark matter to the standard model. While this parameter region is largely immune to direct detection constraints, it predicts an interesting signature of disappearing tracks or displaced vertices at the LHC. We will also discuss the effect of bound state formation of the coannihilating particle which considerably enhanced the valid parameter space into the multi-TeV region, making it a prime target for upcoming long-lived particle searches at the LHC.

The nature and origin of dark matter are among the most compelling mysteries of contemporary science. LUX-ZEPLIN (LZ) is a dark matter direct detection experiment located at the Sanford Underground Research Facility in Lead, South Dakota. The experiment consists of a dual-phase xenon Time Projection Chamber with an active volume of 7 tonnes, surrounded by an active liquid xenon skin region and a gadolinium-loaded liquid scintillator neutron detector. With an exposure of 60 live days using a fiducial mass of 5.5 tonnes, LZ has achieved world-leading sensitivity to Weakly Interacting Massive Particles (WIMPs). This talk will give an overview of the LZ experiment and present results from LZ's first dark matter search.

In quantum many-body systems, measurement tends to kill quantum entanglement and correlations between different degrees of freedom. Nonetheless, recent developments have explored how measurement can be used to engineer new non-equilibrium phases of matter, but mostly in the context of quantum entanglement in random quantum circuits. In this talk, I will first take a different perspective and first examine how a protocol of repeated, periodic measurements can be used to generate chiral transport in a system of free fermions [1], mimicking the anomalous Floquet topological insulators [2]. We will then examine the effects of different types of realistic disorder, namely site blockade, lattice distortions, and random onsite potential on this measurement induced chiral transport. Most notably, one observes a percolation phase transition in the flow of measurement induced chirality with percolation threshold matching previous result on the percolation cluster in a Lieb lattice [3]. Our work demonstrates how measurements can be used to engineer new states of matter, and I will point out future directions on the fundamental role of measurements in the dynamics of quantum many-body systems.

References:

[1] "Stirring by staring: Measurement induced Chirality", arXiv:2108.05906

[2] "Anomalous Edge States and the Bulk-Edge Correspondence for Periodically Driven Two-Dimensional Systems", PRX 3, 031005 (2013).

[3] "Percolation on Lieb Lattices", PRE 104, 064122 (2021).

Tests of Lorentz invariance continue to inform and challenge our modern understanding of spacetime symmetries. Using a model-independent framework based on effective field theory, generic deviations from exact Lorentz and CPT invariance can be studied in a wide class of physical systems. Despite the large number of constraints extracted over the past two decades, stringent limits on many quark-sector effects remain relatively scarce. I discuss the sensitivity of dedicated searches at electron-proton and proton-proton colliders.

The MoEDAL experiment deployed at IP8 on the LHC ring was the first dedicated search experiment to take data at the LHC in 2010.  It was designed to search for Highly Ionizing Particle (HIP) avatars of new physics such as magnetic monopoles, dyons, Q-balls, multiply charged particles, massive slowly moving charged particles and long-lived massive charge SUSY particles. We shall report on our search at LHC’s Run-2 for Magnetic monopoles and dyons produced in p-p and photon-fusion. We will report in a little more detail our most recent result in this arena:  the search for magnetic monopoles via the Schwinger Mechanism in Pb-Pb collisions, that was recently published in Nature.

            The MoEDAL detector will be reinstalled for LHC’s Run-3 to continue the search for electrically and magnetically charged HIPs. As part of this effort we will initiate the search for massive long-very lived SUSY particles to which MoEDAL has a competitive sensitivity.   An upgrade to MoEDAL, the MoEDAL Apparatus for Penetrating Particles (MAPP), approved by CERN’s Research Board is now the LHC’s newest detector. The MAPP detector, positioned in UA83, expands the physics reach of MoEDAL to include sensitivity to feebly-charged particles with charge, or effective charge, as low as 10^-3 e (where e is the electron charge). Also, the MAPP detector In conjunction with MoEDAL’s trapping detector gives us a unique sensitivity to extremely long-lived charged particles. MAPP also has some sensitivity to long-lived neutral particles.

            Additionally, we will briefly report on the plans for the MAPP-2 upgrade to the MoEDAL-MAPP experiment for the High Luminosity LHC (HL-LHC). We envisage that this detector will be deployed in the UGC1 gallery near to IP8. This phase of the experiment is designed to maximize  MoEDAL-MAPP’s sensitivity to very long-lived neutral messengers of physics beyond the Standard Model.

NOvA is a long-baseline neutrino oscillation experiment, designed to make measurements using muon neutrino disappearance and electron neutrino appearance. It consists of two functionally equivalent detectors and utilizes the Fermilab NuMI beam. NOvA uses a convolutional neural network for particle identification of electron neutrino events with a validation process that includes several data-driven techniques. In particular, a suite of studies called the Muon Removed studies checks for bias in our particle identifier between simulation and data arising from potential mismodelling in our simulation by modifying samples of muonic events to create samples of pure electron neutrino like events. This talk will discuss the implementation and results of these techniques being applied to our most recent analysis as well as how these cross checks could be extended to corrections to our predicted electron neutrino signal.

Physics searches and measurements at high-energy collider experiments traditionally focus on the high-pT region. However, if particles are light and weakly-coupled, this focus may be completely misguided: light particles are typically highly collimated around the beam line, allowing sensitive searches with small detectors, and even extremely weakly-coupled particles may be produced in large numbers there. The FASER experiment will use the opportunity and extend the LHC’s physic potential by searching for long-lived particles and study-

ing neutrino interactions at TeV energies. In this talk, I will present the physics potential of FASER for new physics searches, neutrino physics and QCD and astro-particle physics.

Abstract attached. 

In this talk I will review work on `decomposition,' a property of 2d theories with 1-form symmetries and, more generally, d-dim'l theories with (d-1)-form symmetries.  Decomposition is the observation that such quantum field theories are equivalent to ('decompose into’) disjoint unions of other QFTs, known in this context as "universes.” Examples include two-dimensional gauge theories and orbifolds with matter invariant under a subgroup of the gauge group. 

Decomposition explains and relates several physical properties of these theories -- for example, restrictions on allowed instantons arise as a "multiverse interference effect" between contributions from constituent universes. First worked out in 2006 as part of efforts to understand string propagation on generalizations of spaces,  decomposition has been the driver of a number of developments since. 

In the first half of this talk, I will review decomposition; in the second half, I will focus on the recent application to anomaly resolution of Wang-Wen-Witten in two-dimensional finite gauge theories known as orbifolds.

I will present the first oscillation-related results from the MicroBooNE neutrino experiment at Fermilab. These measurements, featuring extensive searches for anomalous rates of both electron neutrinos and neutrino-induced gammas from the Booster Neutrino Beamline with multiple final-state topologies, directly address the 4.8sigma excess of electron-like events seen by the MiniBooNE experiment.
 

The Cryogenic Underground Observatory for Rare Events (CUORE), hosted at the Laboratori Nazionali del Gran Sasso in Italy, is the first one-tonne scale cryogenic experiment searching for neutrinoless double-beta (0νββ) decay of 130Te. The discovery of this process would demonstrate that lepton number is not a symmetry of nature and that neutrinos are massive Majorana particles. The CUORE experiment has also the potential for the search for rare events and/or for physics beyond the Standard Model other than the 0νββ decay. CUORE is currently in stable operating mode, an exposure of more than 1 tonne∙yr has been achieved and the data taking is currently underway to collect 5 years of run time. In this talk, the current results of CUORE's main analyses will be presented, as well as a review of the detector performance and the analysis techniques. The seminar conclusion will provide an insight on the future perspectives of 0vββ decay searches utilising cryogenic calorimeters, mainly the CUPID experiment.

Since the discovery of the SM Higgs boson in 2012, the investigation of the apparent difference between the electroweak and Planck scales has led to more interest in collisions with energies above the electroweak scale. One consequence of this new regime is expanded interest in hadronic final states resulting in collimated sprays of particles called jets. Understanding jets and jet substructure has therefore become of vital interest to particle physicists. In this seminar, I present recent measurements of jet substructure quantities, which can help us better understand multijet systems and to improve machine learning taggers by reducing systematic uncertainties. I also detail my work on jet reconstruction and plans to understand jet substructure at future colliders.

Experimental particle physics is an intensely computational field of science. In fact, particle physicists were arguably the first non-secret (non-cryptography) users of digital computers, and have been pushing the boundaries of pattern recognition and throughput ever since. For decades, our unique needs justified custom software at all levels of the stack, maintained "in-house" by physicists, but the situation changed in the 21st century. Machine learning and analysis of web-scale datasets (i.e. "Big Data") has become an industry on its own, under the catch-all name "data science." Physicists are responding by adopting data science toolsets and methodologies, integrating them with traditional physics software, though the process is ongoing and differs in degree across physics groups. 

This talk will present a big picture of how experimental particle physicists have used data analysis software in the past 75 years, how our needs have dictated a choice of programming languages and toolkits, and how those choices are changing. We'll see how pattern recognition evolved from semi-automated to algorithmic to machine learning, how programming languages transitioned from Fortran to C++ to include a significant mix of Python, and how software was organized from site-custom solutions to standard packages like CERNLIB and ROOT to also include a mix of data science tools. Finally, these choices are not purely technical: communities form around software tools, and integrating toolsets integrates physicists with the larger world.

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. 

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.

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.

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.

Abstract: The LHC is not only the highest energy, but also the highest intensity proton-proton collider ever constructed. In 2016, the LHC exceeded its initial designed luminosity of 10^34 cm-2s-1, and since then, it has further increased to a record setting 2.06E34 cm-2s-1. The increase in luminosity has created a higher occupancy, radiation, and pileup environment, which requires an increasingly robust detector. The first of such adaptations was the CMS phase-I pixel upgrade. This pixel upgrade improved the pixel detector's bandwidth, tracking efficiency, radiation tolerance, and material budget in order to ensure physics performance up to the HL-LHC era. The next proposed tracking upgrade is a complete replacement of the inner and outer tracker. The HL-LHC Outer Tracker Upgrade is a monumental change that increases the detector's granularity, hit coverage, readout speed, triggering capabilities, radiation hardness, and cooling capabilities. This seminar will cover the construction, installation, and performance of the CMS phase-I pixel upgrade and the design, progress, and expected physics performance of the HL-LHC outer tracker upgrade.

A model of radiative neutrino masses which also resolves anomalies reported in B-meson decays, R_D(★) and R_K(★), as well as in muon g −2 measurement, ∆a_µ 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 R_D(★), R_K(★) 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).

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.

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. 

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.  

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.

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.

 

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.

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.

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.

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.

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.

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.
 

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.

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. 

High intensity hadron (pion dominated) beams already made COMPASS the
world leading facility for hadron spectroscopy and  hadron structure
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.

TBA

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.

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.

 

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.

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.

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.

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.
 

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.​

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.

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.

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.

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.

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).

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.

Reserved for Chemistry 3:30 - 5:30pm

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.

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.