ATLAS Study Provides Insight into W Boson Mass

The ATLAS Collaboration at CERN has released a new preliminary result of its W-boson mass measurement, finding it to be 80360 MeV with an uncertainty of just 16 MeV, in agreement with the Standard Model. The measurement was made by fitting the kinematic distributions of the decay leptons in simulation to the data, with improved statistical methods and refinements in the treatment of the data reducing the uncertainty of the mass measurement by more than 15%. Future measurements of the W-boson mass are expected by other LHC experiments.