A note on radiative corrections to $μ$ and $τ$ decays

Abstract

Radiative corrections in the order ${α\over{2π}}{{m^2_e}\over m^2_μ}$ to $μ$- and ${α\over{2π}}{{m^2_μ}\over m^2_τ}$ to $τ$- decays are calculated. The decay width is enhanced by $4.48\cdot 10^{-3} ({α\over{2π}})$ in the muon case and by $0.283 ({α\over{2π}})$ for the $τ\rightarrow μν_τ\barν_μ(γ)$ decay. Influence of these corrections on the electroweak data is discussed.