The $\tau\to\nu_\tau\pi e^+e^-$ decay revisited

Abstract

The recent results from Belle of the $\tau^-\to\nu_\tau\pi^-e^+e^-$ analysis has incentivated us to make a reanalysis of a former work where the Structure Dependent parts are obtained using Resonance Chiral Theory. Here we rely on the same theory accounting for effects that explicitly break such symmetry. A motivation is the involved $W\pi\gamma^\star$ vertex, utterly relevant in computing $\tau^- \to \nu_{\tau}\pi^-$ radiative corrections.