Spontaneous left-right symmetry breaking in supersymmetric models with only Higgs doublets

Abstract

We studied the question of parity breaking in a supersymmetric left-right model, in which the left-right symmetry is broken with Higgs doublets (carrying B-L=±1). Unlike the left-right symmetric models with triplet Higgs scalars (carrying B-L=±2), in this model it is possible to break parity spontaneously by adding a parity-odd singlet. We then discussed how neutrino mass of type-III seesaw can be invoked in this model by adding extra fermion singlets. We considered simple forms of the mass matrices that are consistent with the unification scheme and demonstrate how they can reproduce the required neutrino mixing matrix. In this model, the baryon asymmetry of the Universe is generated via leptogenesis. The required mass scales in the model are then found to be consistent with the gauge coupling unification.