Oblique corrections to the W width

The lowest-order expression for the partial W width to eν, Γ(W→eν)=G_μM_W³ / (6πsqrt[2]), has no oblique radiative corrections from new physics if the measured W mass is used. Here G_μ=(1.166 39±0.000 02)×10^-5 GeV/c² is the muon decay constant. For the present value of M_W=(80.14±0.27) GeV/c², and with m_t=140 GeV/c², one expects Γ(W→eν)=(224.4±2.3) MeV. The total width Γ_tot(W) is also expected to lack oblique corrections from new physics, so that Γ_tot(W) / Γ(W→eν)=3+6[1+{α_s(M_W) / π} ]. Present data are consistent with this prediction.