Lepton flavor violation in $\tau$ decays

Abstract

We study the lepton flavor violation (LFV) in tau decays in the framework of the supersymmetric seesaw mechanism with nonholomorphic terms for the lepton sector at a large $\tan\beta$. In particular, we analyze two new decay modes $\tau\to \ell f_0(980)$ and $\tau\to \ell K^{+} K^{-}$ arising from the scalar boson exchanges contrast to $\tau\to \ell\eta^{(\prime)}$ from the pseudoscalar ones. We find that the decay branching ratios of the two new modes could be not only as large as the current upper limits of $O(10^{-7})$, but also larger than those of $\tau\to \ell \eta^{(\prime)}$. Experimental searches for the two modes are important for the LFV induced by the scalar-mediated mechanism. In addition, we show that the decay branching ratios of $\tau\to \ell \mu^{+} \mu^{-}$ are related to those of $\tau\to \ell \eta$ and $\tau\to \ell f_0(980)$.