The m W − m Z interdependence in the Standard Model: a new scrutiny

Abstract

Abstract: The mW − mZ interdependence in the Standard Model is studied in the MS¯ scheme at the two-loop level, including the known higher-order contributions. The relevant radiative parameters, (Formula presented.) are computed at O(α2) taking into account higherorder QCD corrections and the resummation of the reducible contributions. We obtain mW = 80.357 ± 0.009 ± 0.003 GeV where the errors refer to the parametric and theoretical uncertainties, respectively. A comparison with the known result in the On-Shell scheme gives a difference of ≈ 6 MeV. As a byproduct of our calculation we also obtain the MS¯ electromagnetic coupling and the weak mixing angle at the top mass scale, (Formula presented.) and (Formula presented.).