Measurement of the W-boson mass in pp collisions at √s=7\, TeV s = 7 TeV with the ATLAS detector

A measurement of the mass of the W boson is presented based on proton-proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fb -1 of integrated luminosity. The selected data sample consists of 7.8 10 6 candidates in the W channel and 5.9 10 6 candidates in the W e channel. The W -boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yielding m W = 80370 7 (stat.) 11(exp. syst.)