Thermal Leptogenesis Scenarios in the Restrictive Left-Right Symmetric Model

We investigated thermal leptogenesis scenarios in the left-right symmetricextension of the standard model. In the SO(10) GUT framework, we impose theD-parity realization below GUT scale. These two conditions makes our model morerestrictive and predictive. In such a case, a D-parity odd singlet in the4-index antisymmetric tensor representation of SO(10) have a critical role.This singlet have prospects of causing a very large mass hierarchy betweenSU(2)L and SU(2)R triplet scalars. We test our model by computing baryogenesis via leptogenesis. The heavyright-handed neutrinos N's and the SU(2)L triplet scalar can generate thelepton number asymmetry. Leptogenesis scenarios can be categorized by thesemass scales. If the light neutrinos are Majorana and have a hierarchical massspectrum, we can obtain a successful result in leptogenesis through lightestN-decay. But we found that the normal mass hierarchy of the light neutrinosconflicts with leptogenesis through triplet-decay.Comment: 22 pages, 12 figure