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

TL;DR

This paper analyzes the probability of Z-boson decay into charginos within a strong electromagnetic field, deriving an exact decay width expression and showing the process can occur in superstrong fields even if forbidden in vacuum.

Contribution

It provides an exact analytic expression for the Z-boson decay width into charginos in a strong electromagnetic field, extending understanding of particle decay processes under extreme conditions.

Findings

Decay process forbidden in vacuum for heavy charginos

Decay can occur in superstrong fields ($\varkappa > 1$)

Derived exact decay width expression

Abstract

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 $\Gamma(Z^{0}\rightarrow \chi ^{+} \chi ^{-})$ 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 $Z^0\rightarrow \chi ^{+} \chi ^{-}$ is forbidden in 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 ($\varkappa > 1$).