Leptogenesis in the two right-handed neutrino model revisited
Abstract
We revisit leptogenesis in the minimal non-supersymmetric type I see-saw mechanism with two right-handed (RH) neutrinos, including flavour effects and allowing both RH neutrinos N_1 and N_2 to contribute, rather than just the lightest RH neutrino N_1 that has hitherto been considered. By performing scans over parameter space in terms of the single complex angle z of the orthogonal matrix R, for a range of PMNS parameters, we find that in regions around z \sim \pm \pi/2, for the case of a normal mass hierarchy, the N_2 contribution can dominate the contribution to leptogenesis, allowing the lightest RH neutrino mass to be decreased by about an order of magnitude in these regions, down to M_1 \sim 1.3*10^11 GeV for vanishing initial N_2-abundance, with the numerical results supported by analytic estimates. We show that the regions around z \sim \pm \pi /2 correspond to light sequential dominance, so the new results in this paper may be relevant to unified model building.
Keywords
Cite
@article{arxiv.1107.6002,
title = {Leptogenesis in the two right-handed neutrino model revisited},
author = {S. Antusch and P. Di Bari and D. A. Jones and S. F. King},
journal= {arXiv preprint arXiv:1107.6002},
year = {2015}
}
Comments
41 pages, 10 figures; v2 matches published version in PRD