Implications of supersymmetric SO(10) grand unification

Abstract

We investigate the properties of a class of supersymmetric SO(10) grand unified models with an intermediate mass scale ${M}_{R}$ corresponding to the breaking of left-right symmetry. We consider the possibility that the supersymmetry-breaking scale ${M}_{S}$ coincides with ${M}_{R}$ and study the constraints imposed on the value of ${M}_{R}$ by low-energy parameters such as ${sin}^{2}\ensuremath{\theta}({M}_{W})$ and ${\ensuremath{\alpha}}_{\mathrm{strong}}({M}_{W})$ for different plausible scenarios for the mass spectrum of the supermultiplet fields. We find that the allowed values of ${M}_{R}$ are greater than ${10}^{10}$ GeV. If, however, the supersymmetry-breaking scale ${M}_{S}>{M}_{R}$ and ${M}_{S}$ is chosen as a free parameter, lower intermediate mass scales are possible. Some implications of our model are noted.