The mass of the W boson, a mediator of the weak force between elementary particles, is tightly
constrained by the symmetries of the standard model of particle physics. We measure the W boson mass to be 80433.5 ± 9.4 MeV using data corresponding to 8.8/fb of integrated luminosity √s = 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. The measurement is in tension with the prediction of the standard collected in proton-antiproton collisions at model.