# Past Events

## November 2020

### Jesse Thaler (MIT) “The Hidden Geometry of Particle Collisions”

ABSTRACT: In this talk, I explain how various concepts and techniques in quantum field theory and collider physics can be naturally translated into a new geometric language. Using the energy mover's distance, which quantifies the minimal amount of "work" required to rearrange one event into another, we can define a distance between pairs of collider events.  This distance can then be used to triangulate the "space" of collider events and rigorously define various geometric objects.  Many well-known collider observables, jet…

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## December 2020

### Matt Klein (Michigan) “Search for Higgs boson decays to bottom quarks in the vector boson fusion production mode”

ABSTRACT: The Higgs boson is expected to decay to bb approximately 58% of the time. Despite the large branching fraction, due to the large background from SM events with b-jets, measuring this decay has been less precise than other, less frequent, decays. Measuring H(bb) in the VBF production mode has historically been insensitive, but developments in the background estimates and discrimination, as well as improvements in the signal extraction techniques, have resulted in an observed (expected) significance of 3.0 (3.0)…

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### Zhicai Zhang (CalTech) “Search for Long-Lived Particles with Precision Timing Detectors”

Abstract: Searching for new physics beyond the standard model (BSM) has been one of the main goals of the LHC. With no new physics found in many SUSY and Exotica searches for prompt BSM particles from the LHC data, I will present a new BSM search approach that is looking for new particles with a long lifetime. The search is looking for SUSY long-lived particles that decay to photons, with the final state photon being time-delayed compared to prompt photon…

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### Aniruddha Bapat (University of Maryland, College Park) “Variational Quantum Optimization in the NISQ Era”

ABSTRACT: Quantum information science in the coming decade will likely be carried out on noisy devices consisting of ~100-1000 qubits that do not share full interconnectivity. In this so-called NISQ regime, variational quantum algorithms, which tackle a wide range of problems from areas such as combinatorial optimization, quantum chemistry, and high-energy physics, provide a path to practical quantum advantage. In this talk, I will present some of our recent work that explores the theory behind variational algorithms such as quantum…

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### Michael Kreshchuk (Tuft University) “Quantum simulation of relativistic field theories in the front form”

Abstract:  I will talk about quantum simulation algorithms based on the light-front formulation of quantum field theory. They will range from ab initio simulations with nearly optimal resource scalings to VQE-inspired methods available for existing devices.My work is greatly inspired by the analogy, first noted by Kenneth Wilson, between the light-front formulation of QFT and quantum chemistry. The approach I develop to simulating field theory is an alternative to lattice techniques; it allows one to use methods developed for quantum…

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## January 2021

### Xinran Li (Princeton University) “The energy resolution and the energy deposition processes in noble liquid dark matter detectors”

Abstract:  Noble liquid detectors, especially liquid argon and liquid xenon time projection chambers (TPCs) have been developed and improved during the last decades. They produced the best limits in the search for one of the best motivated dark matter candidates, weakly interacting massive particles (WIPMs), in the O(10)GeV to O(10)TeV mass region. I’ll first talk about the DarkSide-50 low mass analysis which produced the best limit of 5$\times$10^{-42} cm^2 on spin-independent dark matter nuclear scattering cross section for dark matter…

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### Dylan Temples (Northwestern University) New Directions in Liquid Noble Dark Matter Searches: Probing the Sub-GeV Regime

Abstract:  The most sensitive searches for dark matter (DM) with mass above ~10 GeV/c2 use the dual-phase xenon time-projection chamber (LXe-TPC) technology. In the U.S., development of this technology is spearheaded by the LUX-ZEPLIN experiment, with first science data coming soon. As these detectors increase in scale and sensitivity, previously negligible backgrounds become important to understand, both to prevent false discovery claims and to accurately measure the ultimate DM sensitivity of such an experiment. In this talk, I will discuss…

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### Digvijay Wadekar (New York University) “Accelerating analysis of cosmological surveys with novel analytic methods and machine learning”

- Abstract:  In order to infer cosmological parameters from data of upcoming surveys like DESI, we will use summary statistics such as the power spectrum. An accurate estimate of their covariance matrix is crucial for the inference analysis. The traditional process of obtaining the covariance involves thousands of expensive mock simulations. I will present a novel analytic approach to calculate the covariance which is faster by more than four orders of magnitude. I will demonstrate the validation of our analytic approach…

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### Etienne Dreyer (Simon Fraser University) Searching for new physics using high-energy lepton pairs and some other hot topics in ATLAS

Abstract: What is the nature of dark matter? What leads to the fundamental forces having such disparate strengths? Can we explain the small mass of the Higgs boson without excessive fine tuning? These outstanding questions are part of a broad motivation to continue investigating new physics scenarios beyond the Standard Model (SM). Several theoretical solutions propose an extended gauge symmetry group beyond the SM, and hence predict the existence of additional massive gauge bosons. I will discuss the latest search…

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### Nandita Khetan (Gran Sasso Science Institute) “Cosmology in the multi-messenger era”

Abstract:  The talk will present my PhD project research which focuses on advancing the standardization of various transients to be used as cosmological probes and the evaluation of the Hubble constant (H0). With SN Ia, I will present interesting results coming from a recent work where I used an alternate way to calibrate SN Ia based on the surface brightness fluctuations (SBF) method. Besides SNe Ia, I explored other exotic/new transients like Superluminous supernovae, Kilonovae and Gravitational waves as distance…

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