The Minimal Type-I Seesaw Model and Flavor-dependent Leptogenesis

Abstract

In this talk, we first give a brief review of the so-called minimal seesaw models and then concentrate on the minimal type-I seesaw model with two almost degenerate right-handed Majorana neutrinos of $\mathcal{O}(1\mathrm{TeV})$. A specific texture of the neutrino Yukawa coupling matrix is proposed to achieve the nearly tri-bimaximal neutrino mixing pattern. This ansatz predicts (1) ${\theta }_{23}^{}=\pi /4$, $|\delta |=\pi /2$ and ${\sin }^2{\theta }_{12}^{}=(1-2{\tan }^2{\theta }_{13}^{})/3$ in the $m_1^{}=0$ case; and (2) ${\theta }_{23}^{}=\pi /4$ and ${\theta }_{13}^{}=\delta =0$ in the $m_3^{}=0$ case. In both cases, the cosmological baryon number asymmetry can be explained via the resonant leptogenesis mechanism. Finally, we demonstrate the significance of flavor-dependent effects in our leptogenesis scenario.

4 pages. Talk given by Shun Zhou at the 4th International Conference on Flavor Physics, 24-28 September 2007, Beijing (to appear in the proceedings)

References in corpus (2)

• Tri-bimaximal Neutrino Mixing and Flavor-dependent Resonant Leptogenesis
• Neutrino Masses, Lepton Flavor Mixing and Leptogenesis in the Minimal Seesaw Model