Searches for violation of lepton flavour and baryon number in tau lepton decays at LHCb

摘要

Searches for the lepton flavour violating decay τ ? → μ ? μ + μ ? and the lepton flavour and baryon number violating decays τ ? → p ˉ μ + μ ? and τ ? → p μ ? μ ? have been carried out using proton–proton collision data, corresponding to an integrated luminosity of 1.0 ? fb ? 1 , taken by the LHCb experiment at s = 7 ? TeV . No evidence has been found for any signal, and limits have been set at 90 % confidence level on the branching fractions: B ( τ ? → μ ? μ + μ ? ) 8.0 × 10 ? 8 , B ( τ ? → p ˉ μ + μ ? ) 3.3 × 10 ? 7 and B ( τ ? → p μ ? μ ? ) 4.4 × 10 ? 7 . The results for the τ ? → p ˉ μ + μ ? and τ ? → p μ ? μ ? decay modes represent the first direct experimental limits on these channels.