Search for pair production of third-generation leptoquarks decaying into a bottom quark and a τ -lepton with the ATLAS detector
Abstract
A search for pair-produced scalar or vector leptoquarks decaying into a b-quark and a τ -lepton is presented using the full LHC Run 2 (2015-2018) data sample of 139 fb-1 collected with the ATLAS detector in proton- proton collisions at a centre-of-mass energy of
SQUARE ROOT s = 13TeV.
Events in which at least one τ -lepton decays hadronically are considered, and multivariate discriminants are used to extract the signals. No significant deviations from the Standard
Model expectation are observed and 95% confidencelevel upper limits on the production cross-section are derived as a function of leptoquark mass and branching ratio B into a τ -lepton and b-quark. For scalar leptoquarks, masses below 1460GeV are excluded assuming B = 100%, while for vector leptoquarks the corresponding limit is 1650GeV
(1910GeV) in the minimal-coupling (Yang-Mills) scenario.