Nearly Degenerate Neutrino Masses and Nearly Decoupled Neutrino Oscillations

TL;DR

This paper proposes a flavor symmetry breaking scheme that explains nearly degenerate neutrino masses and nearly decoupled oscillations, leading to a natural suppression of certain lepton flavor mixings.

Contribution

It introduces a novel flavor symmetry breaking scheme that accounts for neutrino mass degeneracy and oscillation decoupling, with implications for lepton flavor mixing.

Findings

Neutrino masses are nearly degenerate.

Lepton flavor mixing between the 1st and 3rd families is suppressed.

Atmospheric and solar neutrino oscillations are approximately decoupled.

Abstract

We introduce a simple flavor symmetry breaking scheme, in which charged lepton masses have a strong hierarchy and neutrino masses are almost degenerate. It is possible to obtain a natural suppression of lepton flavor mixing between the 1st and 3rd families as well as the approximate decoupling of atmospheric and solar neutrino oscillations with nearly bi-maximal mixing factors. The similarity and difference between lepton and quark flavor mixing schemes are briefly discussed.