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

In the framework of MSSM the probability of $Z^0$-boson decay to charginos in a strong electromagnetic field, $Z^0\to {\chi }^{+}{\chi }^{-}$, 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 $\mathrm{\Gamma }(Z^0\to {\chi }^{+}{\chi }^{-})$ is obtained at an arbitrary value of the parameter $\varkappa=e m_Z^{-3}\sqrt{-(F_{\mu\nu}q^\nu)^2}$, which characterizes the external-field strength $F_{\mu \nu }$ and $Z^0$-boson momentum $q^{\nu }$. The process $Z^0\to {\chi }^{+}{\chi }^{-}$ is forbidden in vacuum for the case of relatively heavy charginos: $M_{{\chi }^{\pm }}>m_Z\mathrm{/}2$. However in an intense electromagnetic background this reaction could take place in the region of superstrong fields ($\mathrm{\varkappa }>1$).