We show that the neutrino models, as suggested by Low [1], which have an additional Abelian family symmetry and a real Higgs singlet to the default see-saw do not hinder the possibility of successful thermal leptogenesis. For these models (neglecting radiative effects), we have investigated the situation of strong washout in both the one-flavor approximation and when flavor effects are included. The result is that while such models predict that ${\theta }_{13}=0$ and that one light neutrino to be massless, they do not modify or provide significant constraints on the typical leptogenesis scenario where the final asymmetry is dominated by the decays of the lightest right-handed neutrinos.

• Received 20 December 2006

DOI:https://doi.org/10.1103/PhysRevD.75.043510