# The 16th International Workshop on Tau Lepton Physics (TAU2021) (Virtual Edition)

September 27, 2021 to October 1, 2021
Indiana University
America/Indiana/Indianapolis timezone

## Resonances in hadronic three-body decays of 𝜏

Sep 29, 2021, 10:40 AM
20m
Virtual (Indiana University)

### Virtual

#### Indiana University

Oral contribution Tau2021 Abstracts

### Speaker

Mikhail Mikhasenko (University of Bonn (DE))

### Description

Hadronic decays of $\tau$ lepton provide a unique possibility to study dynamics in a three-body hadronic system. Particularly, $\tau^-\to \pi^+\pi^-\pi^-\,\nu$ and $\tau^-\to K^-K^+\pi^-\,\nu$ gives a clear sample of the $a_1(1260)$ decays. While the pionic system is dominated by the $\rho$ intermediate resonance and the system with kaons shows mostly $K^*$ resonances, the two final states are strongly coupled via the scalar sector and $\pi^+\pi^- \leftrightarrow K^+K^-$ transitions. In the talk, I will discuss the consequences of this coupling as a modification of the resonance lineshapes and an appearance of the observable triangle-singularity cusps.