Abstract:
We present a measurement of the W-boson mass using 200/pb of data collected in p-pbar collisions at sqrt(s)=1.96 TeV by the CDF II detector at run II of the Fermilab Tevatron. With a sample of 63 964 W-->enu candidates and 51 128 W-->munu candidates, we measure MW = 80413 +- 34 (stat) +- 34(syst) = 80413 +- 48 MeV/c^2. This is the most precise single measurement of the W-boson mass to date.