First run II measurement of the W boson mass at the Fermilab Tevatron

We describe a measurement of the W boson mass m{sub W} using 200 pb{sup -1} of {radical}(s)=1.96 TeV pp collision data taken with the CDF II detector. With a sample of 63 964 W{yields}e{nu} candidates and 51 128 W{yields}{mu}{nu} candidates, we measure m{sub W}=[80.413{+-}0.034(stat){+-}0.034(sys)=80.413{+-}0.048] GeV/c{sup 2}. This is the single most precise m{sub W} measurement to date. When combined with other measured electroweak parameters, this result further constrains the properties of new unobserved particles coupling to W and Z bosons.