Search for lepton flavor violating $\tau \to \ell V^0$ decays at Belle

Abstract

We have searched for neutrinoless $\tau$ lepton decays into $\ell$ and $V^0$, where $\ell$ stands for an electron or muon, and $V^0$ for a vector meson ($\varphi$, $\omega$, $K^{\ast 0}$ or ${\bar{K}}^{\ast 0}$), using 543 fb${}^{-1}$ of data collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. No excess of signal events over the expected background is observed, and we set upper limits on the branching fractions in the range $(0.7-1.8)\times 10^{-7}$ at the 90% confidence level. These upper limits include the first results for $\ell \omega$ as well as new limits that are $3.6-9.6$ times more restrictive than our previous results for $\ell \varphi$, $\ell K^{\ast 0}$ and $\ell {\bar{K}}^{\ast 0}$.

6 pages, 11 figures, contributed to EPS 2007 and Lepton Photon 2007

Cited by in corpus (1)

• Lepton flavour violating semileptonic tau decays in constrained MSSM-seesaw scenarios