A systematic phenomenological survey mapping leptonic Froggatt-Nielsen charge assignments ('textures') to correlated, testable predictions. Order-one FN charge differences generate the observed charged-lepton and neutrino mass and mixing hierarchies through spurion-suppressed effective Yukawa couplings; the resulting higher-dimensional operators, analyzed in SMEFT, fix the relative rates of charged lepton flavor violation and neutrinoless double beta decay for Dirac, Weinberg-operator Majorana, and type-I seesaw neutrino masses. These correlations let future low-energy CLFV experiments, 0-nu-beta-beta searches, and neutrino mass-ordering measurements discriminate between models and can exclude the Dirac FN scenario if the ordering is inverted.
Presents the first systematic, global survey of leptonic Froggatt-Nielsen (FN) models. The FN mechanism explains Standard-Model fermion mass and mixing hierarchies via a spontaneously broken horizont…