Lepton flavor violating Higgs decay $h\to \mu \tau$ in the littlest Higgs Model with T-parity

Abstract

Inspired by the recent CMS $h\to \mu \tau$ excess, we calculate the lepton flavor violating Higgs decay $h\to \mu \tau$ in the littlest Higgs model with T-parity (LHT). Under the constraints of ${\ell }_i\to {\ell }_j\gamma$, $Z\to {\ell }_i{\bar{\ell }}_j$ and Higgs data, we find that the branching ratio of $h\to \mu \tau$ can maximally reach $\mathcal{O}(10^{-4})$. We also investigate the correlation between $h\to \mu \tau$, $\tau \to \mu \gamma$ and $Z\to \mu \tau$, which can be used to test LHT model at future $e^{+}{e}^{-}$ colliders.

Comments: The analytic expressions of the invariant amplitudes in Appendix B are corrected