On Continuous Flavour Symmetries for Neutrinos

TL;DR

This paper reviews how continuous flavour symmetries, especially in the lepton sector, can explain fermion mass hierarchies, neutrino mass ordering, and mixing matrix differences, contributing to solving the flavour puzzle.

Contribution

It provides an overview of implementing continuous symmetries in the lepton flavour sector, highlighting their role in explaining fermion mass and mixing patterns.

Findings

Continuous symmetries can geometrically relate fermion generations.

Models with these symmetries address neutrino mass ordering.

Symmetry-based approaches help explain quark-lepton mixing differences.

Abstract

Flavour symmetries are fundamental tools in the search for an explanation to the flavour puzzle: fermion mass hierarchies, the neutrino mass ordering, the differences between the mixing matrices in the quark and lepton sector, can all find an explanation in models where the fermion generations undergo specific geometric relations. An overview on the implementation of continuous symmetries in the flavour sector is presented here, focussing on the lepton sector.