Radiative corrections to the decay τ → πντ

Abstract

We have calculated the radiative corrections to the decay τ → π(K)ντ, taking to account internal bremsstrahlung and structure dependent radiation in the radiative decay and point meson, hadronic structure dependent and short distance contributions in the virtual corrections. We display the spectra of the photon energy and of the pion-photon invariant mass in the decay τ → πντγ and compare with the PHOTOS Monte-Carlo. Our result for the radiative correction to the ratio Γ(τ → πντ(γ))/Γ(π → μνμ(γ)) is δRτ/π = (0.16 ± 0.14)% and for the ratio Γ(τ → Kντ(γ))/Γ(K → μνμ(γ)), we obtain δRτ/K = (0.90 ± 0.22) %.