Future Seminars And Colloquia

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Meeting ID: 922 8790 9487
Password: HEPseminar

Monday, November 23, 2020
4:00 PM
Online, Room via Zoom
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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.

Join Zoom Meeting:
https://virginia.zoom.us/j/92287909487
Meeting ID: 922 8790 9487
Password: HEPseminar

Wednesday, December 2, 2020
4:00 PM
Physics Building, Room 204

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"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.

Join Zoom Meeting:
https://virginia.zoom.us/j/92287909487
Meeting ID: 922 8790 9487
Password: HEPseminar

Wednesday, January 6, 2021
4:00 PM
Online, Room via Zoom
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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.

TBA


Monday, February 8, 2021
4:00 PM
Physics Building, Room TBA
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"Quantum optical frequency comb on a chip "


Professor Xu Yi , University of Virginia - ECE and Physics
[Host: Peter Schauss]
ABSTRACT:

Scalability is the central challenge in universal quantum computing, which has long established revolutionary premises, such as exponential speedup of difficult to near-impossible computations. A promising platform towards scalable quantum computing is the quantum optical frequency comb, which leverages optical frequency multiplexing and produces thousands of unconditional EPR entanglement in a single oscillator. In this talk, I will present our recent work to miniaturize the quantum optical frequency comb to a photonic chip for the first time. Our work brings the power of microfabrication to quantum optical applications, and could enable low cost mass-production, which promises additional scalability. I will also briefly discuss the roadmap and the challenges towards scalable quantum computing with integrated photonic frequency combs. 

 

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To add a speaker, send an email to phys-speakers@Virginia.EDU. Please include the seminar type (e.g. Seminars and Colloquia), date, name of the speaker, title of talk, and an abstract (if available).