UNSPECIFIED (2015) Determination of the top-quark pole mass using tt¯ + 1-jet events collected with the ATLAS experiment in 7 TeV pp collisions. Journal of High Energy Physics (10): 121. ISSN 1029-8479
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Abstract
The normalized differential cross section for top-quark pair production in association with at least one jet is studied as a function of the inverse of the invariant mass of the tt¯ + 1-jet system. This distribution can be used for a precise determination of the top-quark mass since gluon radiation depends on the mass of the quarks. The experimental analysis is based on proton-proton collision data collected by the ATLAS detector at the LHC with a centre-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.6 fb−1. The selected events were identified using the lepton+jets top-quark-pair decay channel, where lepton refers to either an electron or a muon. The observed distribution is compared to a theoretical prediction at next-to-leading-order accuracy in quantum chromodynamics using the pole-mass scheme. With this method, the measured value of the top-quark pole mass, m t pole , is: mpolet=173.7±1.5(stat.)±1.4(syst.)+1.0−0.5(theory)GeV. This result represents the most precise measurement of the top-quark pole mass to date.