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
mW = 80370 ± 7 (stat.) ± 11 (exp. syst.) ± 14 (mod. syst.) MeV = 80370 ± 19 MeV,
where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W+ and W− bosons yields mW+ − mW− = −29 ± 28 MeV.
|Original language||English (US)|
|State||Published - Jan 25 2017|
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