Search for Lepton Flavor Violating Decays \tau^\pm \to l^\pm\omega (l = e, \mu)

TL;DR

This study searched for lepton flavor violating decays of tau leptons into lighter leptons and an omega meson using a large dataset, finding no evidence and setting upper limits on the decay probabilities.

Contribution

First search for tau to lepton plus omega decays, establishing new upper limits on their branching ratios with a large data sample.

Findings

No signal observed for the decays.

Upper limits on branching ratios are set at 1.1×10⁻⁷ and 1.0×10⁻⁷.

Results constrain models predicting lepton flavor violation.

Abstract

We have searched for lepton flavor violating decays of a $\tau$ to a lighter-mass charged lepton and an $\omega$ vector mesonusing 384.1 $fb^{-}$ of $e^+e^- $ annihilation data collected with the BABAR detector at the Stanford Linear Accelerator Center PEP-II storage ring. No signal is found, and the upper limits on the branching ratios are determined to be ${\cal B}(\tau^{\pm} \to \mathrm{e}^{\pm} \omega) < 1.1\times10^{-7}$ and ${\cal B}(\tau^{\pm} \to \mu^{\pm} \omega) < 1.0\times10^{-7}$ at 90% confidence level.