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

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

## Feasibility of tau g-2 measurements in ultra-peripheral collisions of heavy ions

Oct 1, 2021, 9:15 AM
20m
Virtual (Indiana University)

### Virtual

#### Indiana University

Oral contribution Tau2021 Abstracts

### Speaker

Evgeny Kryshen (NRC Kurchatov Institute PNPI (RU))

### Description

Anomalous magnetic moment of the tau lepton, $a_\tau = (g_\tau -2)/2$, is a sensitive probe of new physics but is extremely difficult to measure precisely in contrast to electron and muon moments. The best experimental limits were set by the DELPHI collaboration more than 15 years ago in the studies of the ditau production in the $e^+e^- \to e^+e^-\tau^+\tau^-$ process. Ultra-peripheral collisions (UPC) of heavy ions at the LHC may provide a unique opportunity to improve the $a_\tau$ constraints in the studies of ${\rm Pb+Pb} \to {\rm Pb+Pb} \tau^+\tau^-$ process. We review recent proposals to study ditau production via semi-leptonic tau decays in Pb-Pb UPC with the available ATLAS and CMS data and discuss feasibility to explore this process down to low transverse momenta of decay leptons with ALICE and LHCb detectors.

### Primary authors

Evgeny Kryshen (NRC Kurchatov Institute PNPI (RU)) Nazar Burmasov (NRC Kurchatov Institute PNPI (RU)) Paul Alois Buhler (Stefan Meyer Institute for Subatomic Physics (SMI), Austrian Academy of Sciences (AT)) Roman Lavicka (Czech Technical University in Prague (CZ))

### Presentation materials

 2021-10-01-tau.pdf VideoTau2021_Krishen.mp4