Abstract
We address the question of how light the lightest supersymmetric particle neutralino can be to be a reliable cold dark matter (CDM) particle candidate. To this end we perform a combined analysis of the parameter space of the minimal supersymmetric standard model (MSSM) taking into account cosmological and accelerator constraints including those from the radiative b→sγ decay. Appropriate grand unification (GUT) scenarios are considered. We find that the relaxation of gaugino mass unification is sufficient to obtain a phenomenologically and cosmologically viable solution of the MSSM with a neutralino as light as 3 GeV. We find good prospects for the direct detection of these superlight CDM neutralinos via elastic scattering off various nuclei in the forthcoming experiments with low-threshold DM detectors. In a certain sense, these experiments can probe the gaugino mass unification giving constraints on the possible GUT scenarios within the MSSM.
- Received 2 August 1996
DOI:https://doi.org/10.1103/PhysRevD.55.503
©1997 American Physical Society