Search for squarks and gluinos in pp collisions at √s = 13 TeV and 13.6 TeV in events with τ -leptons, jets and missing transverse momentum using the ATLAS detector

Abstract

A search for R-parity-conserving supersymmetry in events with large missing transverse momentum, jetsand at least one hadronically decaying τ -lepton is presented.Both gluino and squark pair production are considered,with the cascade decay of each gluino or squark producingeither a τ -slepton or a τ -sneutrino. Three channels areexamined, requiring either exactly one hadronically decayingτ -lepton and no other leptons, exactly one hadronicallydecaying τ -lepton and at least one other lepton, or two ormore hadronically decaying τ -leptons. Analyses in the threechannels are optimised independently and combined statistically.Two separate analysis strategies, either a cut-and-countor machine-learning approach, are used. The search uses140 fb-1 and 51.8 fb-1 of pp collision data recorded by theATLAS detector at the Large Hadron Collider during 2015-2018 at SQUARE ROOTs = 13 TeV and 2022-2023 at SQUARE ROOTs = 13.6 TeV,respectively. Gluino masses below 2.25 TeV and squark masses up to 1.7 TeV are excluded