Double seesaw mechanism and lepton mixing

TL;DR

This paper introduces a flexible framework for modeling lepton mixing matrices using the double seesaw mechanism and symmetry breaking, applicable to various proposed mixing patterns without requiring supersymmetry or extra dimensions.

Contribution

It provides a general, symmetry-based approach to construct lepton mixing models using the double seesaw mechanism, independent of supersymmetry or higher-dimensional theories.

Findings

Framework can reproduce various lepton mixing matrices

Does not rely on supersymmetry or non-renormalizable terms

Applicable to a wide range of proposed models

Abstract

We present a general framework for models in which the lepton mixing matrix is the product of the maximal mixing matrix U_\omega\ times a matrix constrained by a well-defined Z_2 symmetry. Our framework relies on neither supersymmetry nor non-renormalizable Lagrangians nor higher dimensions; it relies instead on the double seesaw mechanism and on the soft breaking of symmetries. The framework may be used to construct models for virtually all the lepton mixing matrices of the type mentioned above which have been proposed in the literature.