Successful leptogenesis in image unification with a left–right symmetric seesaw mechanism Original Research Article

We study thermal leptogenesis in a broad class of supersymmetric image 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 image 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 (109–1010) GeV range. In the remaining four solutions, leptogenesis is dominated by image 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 1010 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.