Breaking flavor democracy with symmetric perturbations

Abstract

Flavor democracy broken in the fermion mass matrix by means of small perturbations can give rise to hierarchical fermion masses. We study the breaking of the $S_3^L\times S_3^R$ symmetry associated with democratic mass matrices to a smaller exchange symmetry $S_2^L\times S_2^R$ in the charged lepton, up and down quark sectors. An additional breaking of the $S_2^L\times S_2^R$ symmetry is necessary for the down quark mass matrix, which yields arbitrary perturbations in that sector. On the other hand, we require the neutrino mass matrix to be diagonal at the leading order, with the perturbations left arbitrary due to the absence of any guiding symmetry. We show that the interplay between these two kinds of perturbations reproduces the quark and lepton mass and mixing observables for either hierarchy of neutrino masses.

13 pages, 2 figures, 2 tables. Version to appear in PLB

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Cited by in corpus (3)

• Flavor structures of charged fermions and massive neutrinos
• Broken Democracy with Intermediate ${\mathbb{S}}_2\times {\mathbb{S}}_2$ Residual Symmetry and Random Perturbations
• Generating the Cabibbo Angle in Flavored Gauge Mediation Models with Discrete Non-Abelian Symmetries