Chargino Production via Z⁰-Boson Decay in a Strong Electromagnetic Field

In the framework of MSSM the probability of Z⁰-boson decay to charginos in a strong electromagnetic field, Z⁰ → 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(Z⁰ → χ⁺ χ⁻) is obtained at an arbitrary value of the parameter $x=e{m}_Z^{-3}\sqrt{-(F_{\mu v}{q}^v{)}^2}$, which characterizes the external-field strength F_μv and Z⁰-boson momentum q^v. The process Z⁰ → χ⁺ χ⁻ is forbidden in a vacuum for the case of relatively heavy charginos: M_χ ± > m_Z/2. However, in an intense electromagnetic background this reaction could take place in the region of superstrong fields (χ > 1). (paper)