Search for the lepton-flavour-violating decays B0→ K*0τ±e∓

Abstract

A first search at LHCb for the lepton-flavour-violating decays B0 → K*0τ±e∓ is presented. The analysis is performed using a sample of proton-proton collision data, collected with the LHCb detector at a centre-of-mass energy of 13 TeV between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is observed, and upper limits on the branching fractions are determined to be BB0→K∗0τ−e+<5.97.1×10−6 and BB0→K∗0τ+e−<4.95.9×10−6 at the 90% (95%) confidence level. These results correspond to the current most stringent upper limits for b → sτl transitions.