On radiative decay of $Z^{\prime}$ boson

Abstract

In the framework of the extended $SU(2)_{h}\times SU(2)_{l}$ model we study the radiative decay of an extra gauge boson $Z^{\prime}$, $Z^{\prime}\toγZ$. The data analysis results of the CDF collaboration at the Fermilab Tevatron allow one to establish not only the lower bound of the decay probability $Z^{\prime}\toγZ$ normalized to Drell-Yan process $Z^{\prime}\to μ^{+}μ^{-}$, $R(Z^{\prime}\toγZ/μ^{+}μ^{-})> 1.4\times 10^{-5}\cot^{2}ϕ$, but also to estimate the mixing angle $ξ$ between the states $Z^{\prime}$ and $Z$, $|ξ| < 5\times 10^{-2}$, taking into account the additional mixing angle $ϕ$ related to the extended gauge group $SU(2)_{h}\times SU(2)_{l}$. The comparison with the decays $Z^{\prime}\toτ^{+}τ^{-}$ and $Z^{\prime}\to \bar b b$, $Z^{\prime}\to \bar t t$ based on the LEP data is also presented.