CORRECTIONS OF MASS SCALE PREDICTIONS IN SO(10) GRAND UNIFIED THEORY WITH HIGHER-DIMENSIONAL OPERATORS

We calculate the two loop contributions to the predictions of the mass scales in an SO(10) grand unified theory. We consider the modified un ification scale boundary conditions due to the nonrenormalizable highe r dimensional terms arising from quantum gravity or spontaneous compac tification of extra dimensions in a Kaluza-Klein-type theory. We find the range of these couplings which allows left-right symmetry to survi ve till very low energy (as low as approximately TeV) and still be com patible with the latest values of sin2 theta(W) and alpha(s) derived f rom CERN LEP. We consider both the situations when the left-right pari ty is broken and conserved. We consider both supersymmetric and nonsup ersymmetric versions of the SO(10) theory. Taking the D-conserved non- SUSY case as an example, we calculate the effects of moderate threshol d uncertainties at the heavy scale, due to the unknown Higgs boson mas ses, on the gravity induced couplings.