Measurement of the Top Quark Mass from $\sqrt{s}=7$ TeV ATLAS Data using a 3-dimensional Template Fit

The top quark mass has been measured using the template method in the channel t ¯t → lepton+jets (lepton=e, μ) based on ATLAS data recorded in the year 2011. The data were taken at a proton-proton centre-of-mass energy of √s = 7 TeV and correspond to an integrated luminosity of about 4.7 fb−1. This analysis uses a 3-dimensional template technique which determines the top quark mass together with a global jet energy scale factor (JSF), and a relative b-jet to light-jet energy scale factor (bJSF), where light jets refers to u, d, c, s quark jets. The top quark mass is measured to be: $m_{top}$= 172.31 ± 0.23 (stat) ± 0.27 (JSF) ± 0.67 (bJSF) ± 1.35 (syst) GeV or $m_{top}$= 172.31 ± 0.75 (stat + JSF + bJSF) ± 1.35 (syst) GeV, where the uncertainties labelled JSF and bJSF refer to the statistical uncertainties on $m_{top}$ induced by the in-situ determination of these scale factors.