Precision and uncertainties in mass scale predictions in SUSY SO(10) with SU(2)_L x SU(2)_R x U(1)_{B-L} x SU(3)_C intermediate breaking

Abstract

In a class of SUSY SO(10) with $SU(2)_L x SU(2)_R x U(1)_{B-L} x SU(3)_C$ $(g_{2L}\neq g_{2R})$ intermediate gauge symmetry, we observe that the prediction on the unification mass $(M_U)$ is unaffected by Planck-scale-induced gravitational and intermediate-scale-threshold effects, although the intermediate scale $(M_I)$ itself is subject to such corrections. In particular, without invoking the presence of additional lighter scalar degrees of freedom but including plausible and reasonable threshold effects, we find that interesting solutions for neutrino physics corresponding to $M_I\simeq 10^{10}-10^{13}$ GeV and $M_U\simeq (5-6) x 10^{17}$ GeV are permitted in the minimal models. Possibilities of low-mass right-handed gauge bosons corresponding to $M_I\simeq 1-10$ TeV consistent with the CERN-LEP data are pointed out in a number of models when threshold effects are included using effective mass parameters.