Neutrino Masses and Mixing Angles in SUSY-GUT Theories with explicit R-Parity Breaking

In minimal SUSY GUT models the R-parity breaking terms are severely constrained by SU(5) gauge invariance. We consider the particular case where the explicit R-parity breaking occurs only via dimension 2 terms of the superpotential. This model possesses only three R-parity breaking parameters. We have studied the predictions of this model for the neutrino masses and mixing angles at the one-loop level within the framework of a radiatively broken unified supergravity model. We find that this model naturally yields masses and mixing angles that can explain the solar and atmospheric neutrino problems. In addition, there are regions in parameter space where the solution to the solar neutrino puzzle is compatible with either the LSND result or the existence of significant hot dark matter neutrinos.