Search for new physics with diboson production at $\sqrt{s}$=13~TeV with the ATLAS detector

  • David Lack

Student thesis: Phd


In this thesis the search for heavy diboson resonances decaying to two leptons and two quarks is presented. The analysis was performed using 36.1 fb^-1 of proton collision data taken by the ATLAS experiment at the Large Hadron Collider at a centre of mass energy of sqrt{s}=13 TeV. An update with a dataset of 140 fb^-1 is also described. Three benchmark models are used to interpret the results of the analysis, these are a spin-0 Heavy Higgs, a spin-1 Heavy Vector Triplet and a spin-2 Randall-Sundrum Graviton. No new physics was observed and limits were set on the production of the three benchmark models used for the 36.1 fb^-1. A study into the loss of acceptance times efficiency for boosted close-by electrons above a signal mass of ~3 TeV is also presented. This inefficiency was observed to be due to the quality requirements on the electrons. A solution to this problem was found by relaxing these requirements and ultimately using a jet as a boosted dielectron object. These changes resulted in an improvement for the acceptance times efficiency of ~4 times that of the standard selection. This thesis also discusses a study into the inefficiency observed in the muon trigger for close-by muons of ~10% per muon. The results of this investigation was that the inefficiency was due to the tracking in the Muon Spectrometer during the full-scan stage of the muon trigger reconstruction.
Date of Award1 Aug 2020
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorStefan Soldner-Rembold (Supervisor) & Alexander Oh (Supervisor)

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