ATLAS collaboration (2902 authors)Aguilar-Saavedra, Juan AntonioAmor Dos Santos, Susana PatriciaAnjos, NunoAraque, Juan PedroCastro, Nuno FilipeConde Muiño, PatriciaDa Cunha Sargedas De Sousa, Mario JoseFiolhais, MiguelGalhardo, BrunoGomes, AgostinhoGonçalo, RicardoJorge, PedroMachado Miguens, JoanaMaio, AméliaManeira, JoséOleiro Seabra, Luis FilipeOnofre, AntónioPedro, RuteSantos, HelenaSaraiva, JoãoSilva, JoséTavares Delgado, AdemarVeloso, FilipeWolters, Helmut2019-02-042019-02-042018-02-15http://dx.doi.org/10.1140/epjc/s10052-018-5595-5http://hdl.handle.net/10400.26/27440This paper presents a direct measurement of the decay width of the top quark using $t\bar{t}$ events in the lepton+jets final state. The data sample was collected by the ATLAS detector at the LHC in proton–proton collisions at a centre-of-mass energy of 8 TeV and corresponds to an integrated luminosity of 20.2 fb$^{-1}$ . The decay width of the top quark is measured using a template fit to distributions of kinematic observables associated with the hadronically and semileptonically decaying top quarks. The result, $\Gamma _t = 1.76 \pm 0.33~(\text {stat.})~ ^{+0.79-0.68}~(\text {syst.})~\text {GeV}$ for a top-quark mass of 172.5 GeV, is consistent with the prediction of the Standard Model.engjournal article2019-02-04