Abstract
Abstract:
This paper presents a direct measurement of the decay width of the top quark using tt¯ 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, Γ = 1.76 0.33 (stat.) +0.79 (syst.) GeV
−0.68
for a top-quark mass of 172.5 GeV, is consistent with the prediction of the Standard Model.