Breaking flavor democracy with symmetric perturbations

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 S3L×S3R symmetry associated with democratic mass matrices to a smaller exchange symmetry S2L×S2R in the charged lepton, up and down quark sectors. An additional breaking of the S2L×S2R 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.