A search for displaced lepton and track triggers at the ATLAS experiment at the Large Hadron Collider

This thesis describes searches for beyond-the-Standard-Model (BSM) physics within the ATLAS Collaboration at the Large Hadron Collider (LHC), with a focus on displaced leptons and advanced tracking techniques. Displaced leptons, which are not consistent with originating from the primary interaction point, can arise from long-lived particles predicted by BSM theories such as supersymmetry (SUSY), offering a distinctive signature for BSM physics. Three projects are described with the aim of improving the search for BSM signals. The first project involves the search for displaced leptons using the latest LHC Run 3 data collected from 2022 to 2023 with the ATLAS detector, targeting BSM scenarios including SUSY. The second project applies a method called the Hough transform for displaced track pattern recognition to optimize the trigger system for the High-Luminosity LHC (HL-LHC) upgrade that will be performed from 2026 to 2030. The third project explores the use of deep learning techniques to improve the identification of low transverse-momentum leptons, enhancing the efficiency of detecting BSM scenarios that introduce new particles with small mass differences between them. Collectively, these projects advance the search for BSM physics in final states with leptons at the ATLAS experiment at LHC.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Zheng, Kai

Contributors dc:contributor

• Benjamin, Hooberman
• Peng, Jen-Chieh
• Shelton, Jessie
• Cooper, Lance

• Particle Physics
• High Energy Physics
• Lhc
• Atlas
• Cern
• Supersymmetry
• Physics Analysis
• Trigger System
• Pattern Recognition
• Lepton Isolation

Statement dc:rights

• Copyright 2024 Kai Zheng

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/127162

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F127162