Neutralino dark matter in minimal supergravity: Direct detection versus collider searches

We calculate expected event rates for direct detection of relic neutralinos as a function of parameter space of the minimal supergravity model. Numerical results are presented for the specific case of a ⁷³Ge detector. We find significant detection rates (R>0.01events/kg/day) in regions of parameter space most favored by constraints from →BXₛγ and the cosmological relic density of neutralinos. The detection rates are especially large in regions of large tanβ, where many conventional signals for supersymmetry at collider experiments are difficult to detect. If the parameter tanβ is large, then there is a significant probability that the first direct evidence for supersymmetry could come from direct detection experiments, rather than from collider searches for sparticles.