Implications of supersymmetric SO(10) grand unification

We investigate the properties of a class of supersymmetric SO(10) grand unified models with an intermediate mass scale MR corresponding to the breaking of left-right symmetry. We consider the possibility that the supersymmetry-breaking scale MS coincides with MR and study the constraints imposed on the value of MR by low-energy parameters such as sin²θ(MW) and αstrong(MW) for different plausible scenarios for the mass spectrum of the supermultiplet fields. We find that the allowed values of MR are greater than 10¹⁰ GeV. If, however, the supersymmetry-breaking scale MS>MR and MS is chosen as a free parameter, lower intermediate mass scales are possible. Some implications of our model are noted.