Measurement of the top quark mass in the $$t\bar{t}\rightarrow $$ t t ¯ → lepton+jets channel from $$\sqrt{s}=8$$ s = 8 TeV ATLAS data and combination with previous results

Abstract

The top quark mass is measured using a template method in the t t lepton + jets channel (lepton is e or ) using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton-proton centre-of-mass energy of s = 8 TeV and correspond to an integrated luminosity of 20.2 fb -1 . The t t lepton + jets channel is characterized by the presence of a charged lepton, a neutrino and four jets, two of which originate from bottom quarks (b). Exploiting a three-dimensional template technique, the top quark mass is determined together with a global jet energy scale factor and a relative b-to-light-jet energy scale factor. The mass of the top quark is measured to be m top = 172.08 0.39 (stat) 0.82 (syst) GeV. A combination with previous ATLAS m top measurements gives m top = 172.69 0.25 (stat) 0.41 (syst) GeV.