Leptogenesis bound on neutrino masses in left-right symmetric models with spontaneous D-parity violation

Abstract

We study the baryogenesis via leptogenesis in a class of left-right symmetric models, in which D-parity is broken spontaneously. We first discuss the consequence of the spontaneous breaking of D-parity on the neutrino masses. Then we study the lepton asymmetry in various cases, from the decay of right-handed neutrinos as well as the triplet Higgs, depending on their relative masses they acquire from the symmetry breaking pattern. The leptogenesis bound on their masses is discussed by taking into account the low energy neutrino oscillation data. It is shown that a TeV scale leptogenesis is viable if there is an additional source of CP violation like CP-violating condensate in the left-right domain wall. This is demonstrated in a class of left-right symmetric models where D-parity breaks spontaneously at a high energy scale while allowing SU(2)_R gauge symmetry to break at the TeV scale.