A4-based see-saw model for realistic neutrino masses and mixing

Abstract

We present an $A4$-based model where neutrino masses arise from a combination of see-saw mechanisms. The model is motivated by several small mixing and mass parameters indicated by the data. These are ${\theta }_{13}$, the solar mass splitting, and the small deviation of ${\theta }_{23}$ from maximal mixing (= $\pi /4$). We take the above as indications that at some level the small quantities are well-approximated by zero. In particular the mixing angles, to a zero order, should be either 0 or $\pi /4$. Accordingly, in this model the Type-II see-saw dominates and generates the larger atmospheric mass splitting and sets ${\theta }_{23}=\pi /4$. The other mixing angles are vanishing as is the solar splitting. We show how the $A4$ assignment for the lepton doublets leads to this form. We also specify the $A4$ properties of the right-handed neutrinos which result in a smaller Type-I see-saw contribution that acts as a perturbation and shifts the angles ${\theta }_{12}$ and ${\theta }_{13}$ into the correct range and the desired value of $\Delta m_{solar}^2$ is produced. The $A4$ symmetry results in relationships between these quantities as well as with a small deviation of ${\theta }_{23}$ from $\pi /4$. If the right-handed neutrino mass matrix, $M_R$, is chosen real then there is no leptonic CP-violation and only Normal Ordering is admissible. If $M_R$ is complex then Inverted Ordering is also allowed with the proviso that the CP-phase, $\delta$, is large, i.e., $\sim \pi /2$ or $-\pi /2$. The preliminary results from NO$\nu$A favouring Normal Ordering and $\delta$ near $-\pi /2$ imply quasi-degenerate neutrino masses in this model.

v2: 23 pages, 3 figures, Appendix on scalar potential minimization added, Matches with the published version

References in corpus (12)

• Global status of neutrino oscillation parameters after Neutrino-2012
• Global fit to three neutrino mixing: critical look at present precision
• Light Sterile Neutrinos: Models and Phenomenology
• Embedding A4 into left-right flavor symmetry: Tribimaximal neutrino mixing and fermion hierarchy
• Neutrino masses and tribimaximal mixing in the minimal renormalizable supersymmetric SU(5) grand unified model with A4 flavor symmetry
• Neutrino Mixing: $A_4$ Variations
• Nonzero ${\theta }_{13}$ and Leptogenesis in a Type-I See-saw Model with $A_4$ Symmetry
• Lectures on Models of Neutrino Masses and Mixings
• Prediction of Leptonic CP Phase in $A_4$ symmetric model
• Testable constraint on near-tribimaximal neutrino mixing
• Relating small neutrino masses and mixing
• Are the small neutrino oscillation parameters all related?

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