Dissertation/Thesis Abstract

Characterization of the Background Due to Lepton Scattering to the Disappearing Track Signature with the ATLAS Detector
by Baugh, Maxwell C., Ph.D., University of California, Santa Cruz, 2019, 180; 27669434
Abstract (Summary)

Supersymmetry models in which the lightest particle is pure-wino or pure-higgsino have chargino next-to-lightest-particles (NLSP) nearly mass-degenerate with the lightest neutralino, resulting in a lifetime long enough to produce hits in the Pixel Detector but not long enough to produce a full track; this is called the "disappearing track signature". Electrons and muons which traverse the Pixel Detector and Coulomb scatter at a steep angle and therefore fail to be reconstructed as electrons or muons are a significant background to this signature; this is the "lepton scatter background". This lepton scatter background was characterized using 36 fb−1 of integrated luminosity of proton-proton collisions at √s = 13 TeV center-of-mass energy in the ATLAS Detector. Electrons were found to dominate at lower transverse momentum whereas at above about 100 GeV the contributions are similar. Comparison with a representative pure-wino Monte Carlo model suggests a minimum threshold of pT > 100 GeV should be used in the full analysis.

Indexing (document details)
Advisor: Schumm, Bruce
Commitee: Nielsen, Jason, Hance, Michael
School: University of California, Santa Cruz
Department: Physics
School Location: United States -- California
Source: DAI-B 81/7(E), Dissertation Abstracts International
Subjects: Particle physics, Physics
Keywords: Background estimation, Chargino, Disappearing track, Lepton scatter
Publication Number: 27669434
ISBN: 9781392559109
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