Lepton flavor violating semileptonic $τ$ decays $τ\to lP(V)$ in a topcolor scenario

Abstract

The contributions of the neutral top-pion $π_{t}^{0}$ and the non-universal gauge boson $Z'$ predicted by topcolor scenario to the lepton flavor violating $(LFV)$ semileptonic $τ$ decays $τ\to lP(V)$ $(P=π^{0}, η, η' $ and $ V=ρ^{0}, ϕ)$ are discussed. We find that the contributions of $Z'$ to these decay processes are generally larger than those from $π_{t}^{0}$. $π_{t}^{0}$ can only make the value of the branching ratio $Br(τ\to lP)$ in the range of 1$\times10^{-11}$ $\sim$ 1$\times10^{-16}$, which is far below the sensitivity of foreseeable experiments. With reasonable values of the free parameters, the non-universal gauge boson $Z'$ can make the value of the branching ratio $Br(τ^{-}\to μ^{-}ϕ)$ reach 1$\times10^{-7}$, which might approach the observable threshold of near-future experiments.

15 pages. Discussions added, some typos corrected