Search for lepton-flavour-violating decays of the Higgs and Z bosons with the ATLAS detector

Direct searches for lepton flavour violation in decays of the Higgs and Z bosons with the ATLAS detector at the LHC are presented. The following three decays are considered: H→ eτ, H→ μτ, and Z→ μτ. The searches are based on the data sample of proton–proton collisions collected by the ATLAS detector corresponding to an integrated luminosity of 20.3 fb - 1 at a centre-of-mass energy of s=8 TeV. No significant excess is observed, and upper limits on the lepton-flavour-violating branching ratios are set at the 95% confidence level: Br(H→ eτ) < 1.04 % , Br(H→ μτ) < 1.43 % , and Br(Z→ μτ) < 1.69 × 10 - 5.