Chargino production via Z-Boson Decay in a Strong Electromagnetic Field

Abstract

In the framework of MSSM the probability of $Z^0$-boson decay to charginos in a strong electromagnetic field, $Z^0\rightarrow χ^{+} χ^{-}$, is analyzed. The method of calculations employs exact solutions of relativistic wave equations for charginos in a crossed electromagnetic field. Analytic expression for the decay width $Γ(Z^{0}\rightarrow χ^{+} χ^{-})$ is obtained at an arbitrary value of the parameter $\varkappa=e m_Z^{-3}\sqrt{-(F_{μν}q^ν)^2}$, which characterizes the external-field strength $F_{μν}$ and $Z^0$-boson momentum $q^ν$. The process $Z^0\rightarrow χ^{+} χ^{-}$ is forbidden in vacuum for the case of relatively heavy charginos: $M_{χ^{\pm}} > m_Z/2$. However in an intense electromagnetic background this reaction could take place in the region of superstrong fields ($\varkappa > 1$).