ATLAS Event Display: a W boson decays into one muon and one neutrino

Display of a candidate event for a W boson decaying into one muon and one neutrino from proton-proton collisions recorded by ATLAS with LHC stable beams at a collision energy of 7 TeV. The muon (red line) has a transverse momentum of 32.8 GeV and the missing transverse energy is 52.4 GeV (cyan blue line), resulting in a transverse mass of 82.9 GeV of the di-lepton system. Little hadronic activity is measured, indicating a small transverse momentum of the W boson candidate. The event was recorded in June 2011 and was used for the measurement of the W boson mass. Event details: Run Number 183081, Event Number 101291517