Eternal annihilations of light photinos

Abstract

In a class of low-energy supersymmetry models the photino is a natural dark matter candidate. We investigate the effects of post-freeze-out photino annihilations which can generate electromognetic cascades and lead to photo-destruction of ${}^4$He and subsequent overproduction of D and ${}^3$He. We also generalize our analysis to a generic dark matter component whose relic abundance is {\it not} determined by the cross section of the self-annihilations giving rise to electromagnetic showers.

Comments: 13 page LaTeX file (no figures)