Probing Lepton Flavor Violation at the ILC and CLIC

Abstract

Lepton flavor violation in the $\tau \mu$ sector would be a clear sign of Beyond Standard Model physics. We employ the SMEFT framework to study the process $e^{+}{e}^{-}\to \tau \mu$ at the ILC and CLIC. We find that the $e^{+}{e}^{-}$ beam polarizations achievable at these machines allow us to probe the chirality structure of the SMEFT operators. In addition, the high center of mass energy leads to a substantial increase in sensitivity to the four-fermion operators that rivals, and in some cases, surpasses tau decay projections from Belle-II.

Comments: 6 pages, 2 figures