The radiative photino decay into a higgsino

The radiative decay of the photino (γ̄) to a higgsino (H?) is calculated in the minimal supersymmetric electroweak theory coupled to N = 1 supergravity. From the recent analyses on two photon production at PETRA, we find that the possibility that $\text{m}{}_{\mathrm{<mtext>H</mtext><mtext>?</mtext>}}\text{/m}{}_{\mathrm{<mtext>\gamma </mtext><mtext>?</mtext>}}\text{<1}$ is almost excluded, unless $\text{m}{}_{\mathrm{<mtext>\gamma </mtext><mtext>?</mtext>}}\text{?}\text{O}\text{(20)}\text{GeV}$. We also calculated the cross section for $\text{e}{}^{\mathrm{+}}\text{e}{}^{\mathrm{-}}\text{→}\text{γ}\text{?}\text{→γ}\text{H}\text{?}\text{+γ}\text{H}\text{?}$ as a function of photon energy.