Lepton flavor violating signals of the neutral top-pion in future lepton colliders

Abstract

The presence of the top-pions ${\pi }_t^{0,\pm }$ in the low-energy spectrum is an inevitable feature of the topcolor scenario. Taking into account the constraints of the present experimental limit of the lepton flavor violating($LFV$) process $\mu \to e\gamma$ on the free parameters of topcolor-assisted techicolor(TC2) models, we study the contributions of the neutral top-pion ${\pi }_t^0$ to the $LFV$ processes ${\mu }^{+}{\mu }^{-}\to \tau \mu$ (or $\tau e$), $\gamma \gamma \to \tau \mu$ (or $\tau e$), $e^{+}{e}^{-}\to \tau \mu$, and $e\gamma \to e{\pi }_t^0\to e\tau \mu (e)$ via the flavor changing ($FC$) couplings ${\pi }_t^0{l}_i{l}_j$ and discuss the possibility of searching for the $LFV$ signals via these processes in future lepton colliders.

Comments: References added, some typos corrected. Version to be published in Phys. Rev. D