Lepton flavor violation in $τ$ 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 $\tanβ$. In particular, we analyze two new decay modes $τ\to \ell f_0(980)$ and $τ\to \ell K^{+} K^{-}$ arising from the scalar boson exchanges contrast to $τ\to \ellη^{(\prime)}$ 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 $τ\to \ell η^{(\prime)}$. 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 $τ\to \ell μ^{+} μ^{-}$ are related to those of $τ\to \ell η$ and $τ\to \ell f_0(980)$.