Abstract
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 × 106
candidates in the W → µν channel and 5.9 × 106 candidates in the W → eν 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...