Quasi-degenerate neutrinos in SO(10)

Abstract

Quark lepton universality inherent in grand unified theories based on $SO(10)$ gauge group generically leads to hierarchical neutrino masses. We propose a specific ansatz for the structure of Yukawa matrices in $SO(10)$ models which differ from this generic expectations and lead to quasi degenerate neutrinos through the type-I seesaw mechanism. Consistency of this ansatz is demonstrated through a detailed fits to fermion masses and mixing angles all of which can be explained with reasonable accuracy in a model which uses the Higgs fields transforming as $10,120$ and $\overline{126}$ representations of $SO(10)$. The proposed ansatz is shown to follow from an extended model based on the three generations of the vector like fermions and an $O(3)$ flavour symmetry. Successful numerical fits are also discussed in earlier proposed models which used combination of the type-I and type-II seesaw mechanisms for obtaining quasi degenerate neutrinos. Large neutrino mixing angles emerge as a consequence of neutrino mass degeneracy in both these cases.

12 pages

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Cited by in corpus (7)

• An SO(10)XS4 Model of Quark-Lepton Complementarity
• Lepton Masses and Flavor Violation in Randall Sundrum Model
• Flavour symmetries in a renormalizable SO(10) model
• Quasi-Degenerate Neutrino Masses with Normal and Inverted Hierarchy
• Quasi-degenerate Neutrino mass models and their significance: A model independent investigation
• SO(10) unification with horizontal symmetry
• The Effects of Majorana Phases in Estimating the Masses of Neutrinos