2005/02/28 by David Atwood, Shaouly Bar-Shalom, Amarjit Soni
Physics and Astronomy · #Cosmology and Gravitation Theories #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1016/j.physletb.2006.02.033
published as Phys.Lett. B635 (2006) 112-117 · 2 pages, 2 figures. Important changes made in v2: 1) improved presentation of leptogenesis and 2) a more elaborate discussion on the assumed texture zeros in the neutrino Yukawa sector. Important changes made in v3: minor changes added to emphasize that in our model the CP-asymmetry in the decays of the lightest Majorana is enhanced by tan^2(beta)~O(100) compared to models with one Higgs doublet as well as with respect to the MSSM
arxiv created 2006/02/08 · openalex publication_date 2006/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We examine neutrino oscillations in a two Higgs doublet model (2HDM) in which the second doublet couples only to the third generation right-handed up-fermions, i.e., to tR and to N3 which is the heaviest right-handed Majorana neutrino. The inherently large tan(beta) of this model can naturally account for the large top mass and, based on a quark-lepton similarity ansatz, when embedded into a seesaw mechanism it can also account for the observed neutrino masses and mixing angles giving a very small θ13: -0.017 < θ13 < 0.021 at 99% CL, and a very restrictive prediction for the atmospheric mixing angle: 42.90 < θatm < 45.20 at 99% CL. The large value of tan(beta) also sets the mass scale of the heaviest right-handed Majorana neutrino N3 and triggers successful leptogenesis through a CP-asymmetry in the decays of the N1 (lightest right-handed Majorana) which is tan2(beta) enhanced compared to the CP-asymmetry obtained in models for leptogenesis with one Higgs doublet or in the MSSM. This enhancement allows us to relax the lower bound on MN1 and consequently also the lower bound on the reheating temperature of the early universe.