Matter Antimatter Asymmetry and Neutrino Properties

Abstract

The cosmological baryon asymmetry can be explained as remnant of heavy Majorana neutrino decays in the early universe. We study this mechanism for two models of neutrino masses with a large \nu_\mu-\nu_\tau mixing angle which are based on the symmetries SU(5) x U(1)_F and SU(3)_c x SU(3)_L x SU(3)_R x U(1)_F, respectively. In both cases B-L is broken at the unification scale \Lambda_{GUT}. The models make different predictions for the baryogenesis temperature and the gravitino abundance.

Comments: latex2e, 14 pages, 2 figures, Contribution to the Festschrift for L. B. Okun, to appear in a special issue of Physics Reports, eds. V. L. Telegdi and K. Winter