Are neutrino oscillation mixings linked to the smallness of solar neutrino scale?

TL;DR

This paper proposes that neutrino oscillation mixings are intrinsically linked to the small solar neutrino mass scale, using a power series expansion of the neutrino mass matrix based on the mass ratio, offering insights into neutrino hierarchies and CP violation.

Contribution

It introduces a novel approach to relate neutrino mixing angles to the solar neutrino scale through a power series expansion of the mass matrix, applicable to different hierarchies and CP phases.

Findings

Neutrino mixing angles can be expressed as a power series in the mass ratio.

The proposed textures are stable under renormalization group evolution.

The approach explains the smallness of solar neutrino oscillation scale.

Abstract

Observed reactor and atmospheric neutrino oscillation mixing values appear to be related to the neutrino scale ratio $\sqrt{\Delta m^2_{sol}/\Delta^2_{ATM}}$ in a way that suggest that the neutrino mass matrix can be expanded as a power series by using this ratio as the smallness parameter. This approach provides a simple and natural way to expose the inner hierarchies among neutrino mass terms, which amounts to also explain the solar oscillation mixing as well as solar oscillation scale. We explore a class of mass matrix textures that realize this scenario, for both normal and inverted neutrino mass hierarchies, as well as CP violation and their stability under renormalization scaling.