Supersymmetric Dark Matter Below the W Mass

A light neutralino, with mass below mW, is considered as a candidate for dark matter. It is found that, in minimal supersymmetry, for predominantly gaugino‐like and higgsino‐like neutralinos the relic mass density is naturally close to the critical density, while for a general superposition of both gauginos and higgsinos it is typically very small. If at least one light sfermion exists, then a light gaugino‐like neutralino also becomes cosmologically less attractive.