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

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

## Search for charged lepton flavor violation at BESIII

Sep 28, 2021, 8:00 AM
25m
Virtual (Indiana University)

### Virtual

#### Indiana University

Oral contribution Tau2021 Abstracts

### Speaker

Dayong Wang (Peking University)

### Description

The charged Lepton Flavor Violation (cLFV) is highly suppressed in the Standard Model (SM) by the finite but tiny neutrino masses. Its branching fraction is calculated to be at a negligible level and so far none has been found in all the historical experiments, including searches in lepton ($\mu$,$\tau$) decays, pseudoscalar meson (K,$\pi$) decays, vector meson ($\phi$,$J/\psi$,$\Upsilon$) decays, Higgs decays etc. This talk reviews the charged Lepton Flavor Violation process searches at BESIII experiement. Besides the result for the decay of $J/\psi\to e\mu$ published earlier, the decay of Jpsi-> e tau, with
tau->pi- pi0 nv_tau is searched with the 10 Billion $J/\psi$ events
collected by BESIII and the result improves the previously published limit by two orders of magnitude. Future perspectives will also be discussed.

What is your topic? Lepton universality and flavour violation

### Primary author

Dayong Wang (Peking University)

### Presentation materials

 VideoTau2021_Wang.mp4 Wang_20210928_Tau2021_BES3CLFV.pdf