ATLAS collaboration (2846 authors)Aguilar-Saavedra, Juan AntonioAmor Dos Santos, Susana PatriciaAnjos, NunoAraque, Juan PedroCantrill, RobertCarvalho, JoãoCastro, Nuno FilipeConde Muiño, PatriciaDa Cunha Sargedas De Sousa, Mario JoseFiolhais, MiguelGalhardo, BrunoGomes, AgostinhoGonçalo, RicardoJorge, PedroLopes, LourencoMachado Miguens, JoanaMaio, AméliaManeira, JoséOleiro Seabra, Luis FilipeOnofre, AntónioPalma, AlbertoPedro, RuteSantos, HelenaSaraiva, JoãoSilva, JoséTavares Delgado, AdemarVeloso, FilipeWolters, Helmut2019-02-042019-02-042017-02-04http://dx.doi.org/10.1140/epjc/s10052-017-4624-0http://hdl.handle.net/10400.26/27077Direct 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\rightarrow e\tau $ , $H\rightarrow \mu \tau $ , and $Z\rightarrow \mu \tau $ . 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  $\mathrm{fb}^{-1}$ at a centre-of-mass energy of $\sqrt{s}=8$  TeV. No significant excess is observed, and upper limits on the lepton-flavour-violating branching ratios are set at the 95 $\%$ confidence level: Br $(H\rightarrow e\tau )<1.04\%$ , Br $(H\rightarrow \mu \tau )<1.43\%$ , and Br $(Z\rightarrow \mu \tau )<1.69\times 10^{-5}$ .engjournal article2019-02-04