Search for lepton flavor violation at future lepton colliders

Abstract

Lepton flavor violating (LFV) processes via four-Fermi contact interactions at future International Linear Collider (ILC) are studied. The effective Lagrangian is composed of six-operators, and the LFV effects on both $e^{+}{e}^{-}\to e^{+}{\ell }^{-}$ and $e^{-}{e}^{-}\to e^{-}{\ell }^{-}$ ($\ell =\mu$ or $\tau$) processes can be parametrized by three parameters. Taking account of previous experimental results of LFV processes $\mu \to 3e$ and $\tau \to 3e$, we find that the upper limits on the LFV parameters for $\ell =\tau$ could be improved at the ILC experiment using the polarized electron beam. The improvement of the upper limits is more than an order of magnitude smaller than previous ones.

Comments: 11 pages, 3 figures