A note on radiative corrections to $\mu$ and $\tau$ decays

Abstract

Radiative corrections in the order $\frac{\alpha }{2\pi }\frac{m_e^2}{m_{\mu }^2}$ to $\mu$- and $\frac{\alpha }{2\pi }\frac{m_{\mu }^2}{m_{\tau }^2}$ to $\tau$- decays are calculated. The decay width is enhanced by $4.48\cdot 10^{-3}(\frac{\alpha }{2\pi })$ in the muon case and by $0.283(\frac{\alpha }{2\pi })$ for the $\tau \to \mu {\nu }_{\tau }{\bar{\nu }}_{\mu }(\gamma )$ decay. Influence of these corrections on the electroweak data is discussed.

Comments: 5 pages, REVTeX, reference added