Department of Physics & Astronomy
University of New Mexico

Nuclear, Particle, Astroparticle and Cosmology (NUPAC) Seminars

Study of the rare decays B_(s)^0→μ^+ μ^- in ATLAS, new simulation techniques for ATLAS events, and development of fast timing detectors for future particle physics experiments

Presented by Josef Sorenson, UNM

Many extensions of the Standard Model predict deviations of the rates of the rare processes B_(s)^0→μ^+ μ^- relative to the Standard Model predictions. Illuminating New Physics requires maximizing precision on measurements of these rare processes. To accomplish this, the branching ratio measurement technique applied by ATLAS uses the high statistics reference channel B^+->J/psi(->mu^+mu^-)K^+. I will discuss data analysis methods for extraction of the reference channel yield, including Monte Carlo modeling, simultaneous functional fits, and systematic error extraction for the ATLAS Full Run 2 data set.

Secondly, I will discuss a software tool designed to expedite simulation of events in the ATLAS detector, an essential step for accumulating the large data sets needed to model extremely rare decays. This tool relies on parameterization of the calorimeters, which account for 80% of the simulation time expended by GEANT4.

At the High Luminosity Large Hadron Collider, where the ultimate measurement of the B_(s)^0→μ^+ μ^- channels may be made, event reconstruction will be challenged by the anticipated 200 simultaneous collisions per beam crossing. I will discuss UNM studies of Low Gain Avalanche detectors, a technology which may offer unprecedented timing resolution which will mitigate the effects of this pileup.

2:00 pm, Tuesday, August 30, 2022

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