Measurement of the top-quark mass using 7 TeV proton-proton collisions with the ATLAS detector

Abstract

The top quark is the heaviest known elementary particle. Its mass is intriguingly close to the electroweak symmetry breaking scale. Therefore its accurate determination is an important aspect of the LHC physics program. A summary of the present measurements of the top-quark mass with the ATLAS detector is presented here. The data used in those analyses amounts up to 4.7/fb of proton-proton collisions at 7 TeV with the Large Hadron Collider. The top-quark mass has been measured in different event topologies, namely all-hadronic, lepton plus jets and dilepton channel. The kinematic approach to measure the top-quark mass uses template methods for the all-hadronic and lepton plus jets channels, and the m_T2 variable, that relates the transverse mass of the two leptons, is used in the dilepton channel.