Speaker
Description
This talk will present a search for scalar leptoquarks in btautau final state using a data sample corresponding to 139 ifb of proton–proton collisions recorded at a center-of-mass energy of $\sqrt{s}$= 13 TeV with the ATLAS detector at the Large Hadron Collider. The signal benchmark model considered is a scalar leptoquark with an electric charge of 4/3e and quantum numbers 3B + L = -2, which decays exclusively into a b-quark and a tau-lepton. The talk will outline the main part of the analysis, from the event selection to the background estimation and the result extraction through a fit performed on the signal regions.
No significant excess above the Standard Model prediction is observed in the explored leptoquark mass range (0.4-2.5 TeV), and 95% confidence-level upper limits are set on the production cross-section times branching fraction of leptoquarks decaying to b-tau. Based on the analysis results leptoquark masses below 1.26~TeV, 1.30~TeV and 1.41~TeV are excluded for a scalar leptoquark Yukawa coupling to b-quark and tau-lepton of 1.0, 1.7 and 2.5, respectively.
