Search for Lepton Flavor Violating Decays $\tau^\pm \to \ell^\pm{\pi^0}, \ell^\pm\eta, \ell^\pm{\eta^\prime}$

TL;DR

This study searched for rare lepton flavor violating decays of the tau lepton into a lighter lepton and a pseudoscalar meson, using extensive data from the BaBar experiment, but found no evidence and set stringent upper limits.

Contribution

First comprehensive search for tau lepton flavor violating decays into a lepton and pseudoscalar mesons using BaBar data, establishing new upper limits.

Findings

No evidence of lepton flavor violation observed.

Upper limits on branching fractions are at the 10^{-7} level.

Results constrain new physics models predicting such decays.

Abstract

A search for lepton flavor violating decays of the $\tau$ lepton to a lighter mass lepton and a pseudoscalar meson has been performed using 339 fb$^{-1}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy near 10.58 GeV by the BaBar detector at the SLAC PEP-II storage ring. No evidence of signal has been found, and upper limits on the branching fractions are set at $10^{-7}$ level.