Precision measurement of W mass at LHC

The W mass allows for a precise cross check of the Standard Model (SM), and its uncertainty is the limiting factor for sensitivity to the SM Higgs mass and what may lie beyond. A precise W mass measurement is feasible at the LHC due to large number of events, not only for W decays, but also corresponding Z decays, which will be the key ingredients for precision calibration and understanding of systematic errors. Using statistics corresponding to 10fb−1 of data at the LHC, we have investigated strategies for improving the uncertainty on the mass measurement beyond 15 MeV, including both theoretical and experimental effects. No single source of uncertainty necessarily contribute more than 5 MeV to the overall uncertainty.