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