Revisiting mono-tau tails at the LHC
Résumé
We revisit the constraints on semileptonic operators derived from the mono-$\tau $ high-$p_T$ events in pp collisions at LHC. Like in previous studies, we obtain limits on the New Physics couplings from the CMS data much stronger than from the ATLAS data, despite a nearly equal integrated luminosity. We find that a neglected systematics on the $\tau $ lepton reconstruction efficiency can partly explain that difference. We then provide new limits on the New Physics couplings relevant to decays based on $b\rightarrow c\tau {\bar{\nu }}$ by using the recent ATLAS data with $139\,\mathrm{fb}^{-1}$. We also show that the inclusion of propagation of the New Physics particle can significantly worsen the bounds obtained by relying on Effective Field Theoretical treatment of New Physics.