# 19th International Conference on Hadron Spectroscopy and Structure in memoriam Simon Eidelman

26-31 July 2021
Mexico City
Mexico/General timezone
HADRON 2021 is over. Thanks for making it a success!
Home > Timetable > Session details > Contribution details

Mexico City -

# A new theoretical determination of R_(tau/P) (P=pi,K)

## Speakers

• Ignasi ROSELL

## Abstract

We determine $R_{\tau/P}\equiv \Gamma(\tau \to P \nu_\tau [\gamma]) / \Gamma(P \to\mu \nu_\mu[\gamma])$ ($P=\pi, K$). Whereas $P$ decays are calculated by using Chiral Perturbation Theory (ChPT), $\tau$ decays are studied with an effective approach where ChPT is enlarged by including the lightest resonances and following the high-energy behavior dictated by QCD. These ratios allow us to test the lepton universality and the unitarity and also to search for bounds on non-standard interactions.