Speaker
Description
A search for singly-produced scalar leptoquarks decaying to $b\tau$ in proton-proton collisions is performed using Run 2 data from LHC corresponding to an integrated luminosity of 139 fb$^{-1}$ at $\sqrt{s}=$13 TeV recorded by the ATLAS detector. The signal benchmark model considered is a scalar leptoquark with an electric charge of 4/3$e$ and quantum numbers $3B+L=-2$, which decays exclusively into a $b$-quark and a $\tau$-lepton. The mass range searched is from 0.4 TeV to 2.5 TeV. No significant excess above the Standard Model prediction is observed, and 95% confidence-level upper limits are provided on the production cross-section times branching fraction of leptoquarks decaying to $b\tau$. Considering both single and pair leptoquark production processes, under the assumption of exclusive decays of scalar leptoquarks to $b\tau b\tau$, leptoquark masses below 1.26 TeV, 1.30 TeV and 1.41 TeV are excluded for a for a Yukawa coupling to $b$-quark and $\tau$-lepton of 1.0, 1.7 and 2.5.
