A direct search for lepton-flavour-violating H → μτ decays of the recently discovered Higgs boson with the ATLAS detector at the LHC is presented. The analysis is performed in the H → μτhad channel, where τhad is a hadronically decaying τ -lepton. The search is based on the data sample of proton-proton collisions collected by the ATLAS experiment corresponding to an integrated luminosity of 20.3 fb−1 at a centre-of-mass energy of TeV. No statistically significant excess of data over the predicted background is observed. The observed (expected) 95% confidence-level upper limit on the branching fraction, Br(H → μτ ), is 1.85% (1.24%).

Aad, G., Abbott, B., Abdallah, J., Abdinov, O., Aben, R., Abolins, M., et al. (2015). Search for lepton-flavour-violating H → μτ decays of the Higgs boson with the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS, 2015(11), 1-33 [10.1007/JHEP11(2015)211].

Search for lepton-flavour-violating H → μτ decays of the Higgs boson with the ATLAS detector

F. Ceradini;B. Di Micco;R. Di Nardo;D. Orestano;F. Petrucci;D. Puddu;G. Salamanna;M. Sessa;