A Search for New Resonant Phenomena in Dijet Final States With the ATLAS Detector at the Large Hadron Collider

Abstract

This dissertation describes a model-agnostic search for new resonant phenomena decaying to two jets (dijets) in 3.6 fb-1 of proton-proton collisions at center-of-mass energy sqrt(s)=13 TeV. The collisions were produced by the Large Hadron Collider and recorded by the ATLAS detector in 2015. A dijet invariant mass spectrum is examined for local excesses above a data-driven background estimation accounting for Standard Model production. No statistically significant excess is observed. New physics models are excluded at 95% credibility-level for quantum black holes with production mass thresholds below 5.3 TeV, 8.1 TeV, and 8.3 TeV for three different production scenarios and for excited quarks of masses less than 5.2 TeV. Furthermore, limits are provided on generic Gaussian signal shapes for additional generalization of the 2015 dijet resonant analysis search results.