Successful Leptogenesis in SO(10) Unification with a Left-Right Symmetric Seesaw Mechanism

Abstract

We study thermal leptogenesis in a broad class of supersymmetric SO(10) models with a left-right symmetric seesaw mechanism, taking into account flavour effects and the contribution of the next-to-lightest right-handed neutrino supermultiplet. Assuming M_D = M_u and a normal hierarchy of light neutrino masses, we show that four out of the eight right-handed neutrino mass spectra reconstructed from low-energy neutrino data can lead to successful leptogenesis with a reheating temperature in the (10^9 - 10^10) GeV range. In the remaining four solutions, leptogenesis is dominated by N_2 decays, as in the type I seesaw case. We find that some of these spectra can generate the observed baryon asymmetry for reheating temperatures above 10^10 GeV, in contrast to the type I case. Together with flavour effects, an accurate description of charged fermion masses turns out to be a crucial ingredient in the analysis.

Comments: 32 pages, 23 figures. v2: 2 comments [below Eq. (53) and at the end of the conclusions] and 1 reference added, typos corrected. Version to be published in Nucl. Phys. B