Search for squarks and gluinos in pp collisions at $$\sqrt{s} = 13$$ TeV and 13.6 TeV in events with $$\tau $$-leptons, jets and missing transverse momentum using the ATLAS detector

UNSPECIFIED (2025) Search for squarks and gluinos in pp collisions at $$\sqrt{s} = 13$$ TeV and 13.6 TeV in events with $$\tau $$-leptons, jets and missing transverse momentum using the ATLAS detector. European Physical Journal C: Particles and Fields, 85 (12): 1437. ISSN 1434-6044

Abstract

A search for R-parity-conserving supersymmetry in events with large missing transverse momentum, jets and at least one hadronically decaying $$\tau $$ τ -lepton is presented. Both gluino and squark pair production are considered, with the cascade decay of each gluino or squark producing either a $$\tau $$ τ -slepton or a $$\tau $$ τ -sneutrino. Three channels are examined, requiring either exactly one hadronically decaying $$\tau $$ τ -lepton and no other leptons, exactly one hadronically decaying $$\tau $$ τ -lepton and at least one other lepton, or two or more hadronically decaying $$\tau $$ τ -leptons. Analyses in the three channels are optimised independently and combined statistically. Two separate analysis strategies, either a cut-and-count or machine-learning approach, are used. The search uses 140 $$\textrm{fb}^{-1}$$ fb - 1 and 51.8 $$\textrm{fb}^{-1}$$ fb - 1 of pp collision data recorded by the ATLAS detector at the Large Hadron Collider during 2015–2018 at $$\sqrt{s} = 13$$ s = 13 TeV and 2022–2023 at $$\sqrt{s} = 13.6$$ s = 13.6 TeV, respectively. Gluino masses below 2.25 TeV and squark masses up to 1.7 TeV are excluded