Constraints on the Minimal SUSY SO(10) Model from Cosmology and the $b\to s \gamma$ Decay

Abstract

It is shown that the minimal supersymmetric SO(10) model with electroweak radiative breaking and universal soft mass terms at the GUT scale is strongly disfavoured by the combination of constraints from the $b\to s \gamma$ decay and the condition $\Omega h^2 < 1$ for the lightest (stable) neutralino. The constraints are, however, easily satisfied for certain class of supersymmetric SO(10) models with non--universal scalar masses which gives small supersymmetric corrections to the bottom quark mass and light higgsino--like neutralinos.