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

Abstract

Abstract

A first search for the lepton-flavour violating decays B0 → K*0τ±μ∓ is presented. The analysis is performed using a sample of proton-proton collision data, collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV between 2011 and 2018, corresponding to an integrated luminosity of 9 fb−1. No significant signal is observed, and upper limits on the branching fractions are determined to be

B

B 0

→

K

∗ 0

τ +

μ −

< 1.0

1.2

×

10

− 5

$$ \mathcal{B}\left({B}^0\to {K}^{\ast 0}{\tau}^{+}{\mu}^{-}\right)<1.0(1.2)\times {10}^{-5} $$ and

B

B 0

→

K

∗ 0

τ −

μ +

< 8.2

9.8

×

10

− 6

$$ \mathcal{B}\left({B}^0\to {K}^{\ast 0}{\tau}^{-}{\mu}^{+}\right)<8.2(9.8)\times {10}^{-6} $$ at the 90% (95%) confidence level.