Probing Muon + b-Jet Resonances in pp Collisions with the ATLAS Detector

Abstract

Probing heavy resonances in collider physics has been a longstanding and fruitful endeavor. Despite well-motivated candidates like leptoquarks and their role in grand unified theories, direct experimental searches for lepton–quark resonances in proton–proton collisions are relatively scarce. Cross-generational lepton–quark resonances have received even less experimental attention. This thesis presents an ATLAS search for one such under-represented resonance: the muon and b-jet resonance. The search leverages the full Run 2 and partial Run 3 datasets at √s = 13 TeV and √s = 13.6 TeV, respectively. For a measure of sensitivity, a benchmark leptoquark $\tilde{S}_1$ model with only muon and b-quark Yukawa couplings is used. Using the CLs statistical method, the analysis improves upon prior leptoquark mass exclusion limits for couplings above ~1.