New gauge boson Z' and lepton flavor violating decays and production of vector mesons

Abstract

Considering the constraints on the lepton flavor violating (LFV) couplings of the new gauge boson $Z'$ to ordinary leptons from the experimental upper limit for the LFV process $\ell\rightarrow 3\ell'$, we calculate the contributions of $Z'$ to the LFV decays $V\rightarrow\ell_{i}\ell_{j}$ with $V\in\{ϕ,J/Ψ,Ψ(2S),Υ^{(n)}\}$ and $τ\toμ(e)ϕ$ in the context of several $Z'$ models. We find that all $Z'$ models considered in this paper can produce significant contributions to these decay processes and make the value of the branching ratio $Br(τ\to eϕ)$ above its experimental upper limit. The experimental upper limit of $τ\to eϕ$ can give more severe constraints on these $Z'$ models than those given by the rare decay process $τ\to3e$.

Reference added, remove some typos; to be published in PRD