Neutrino mixing and see-saw mechanism

TL;DR

This paper explores models of neutrino masses that naturally explain maximal mu-tau mixing and different mass-squared differences, aligning with Super-Kamiokande observations and solar neutrino oscillation data.

Contribution

It identifies two classes of models that account for observed neutrino mixing patterns and mass hierarchies, advancing understanding of neutrino mass mechanisms.

Findings

Models explain maximal mu-tau mixing observed by Super-Kamiokande.

Two classes of models correspond to different neutrino mass hierarchies.

Results align with solar neutrino oscillation data.

Abstract

Models of neutrino masses are discussed capable of explaining in a natural way the maximal mixing between $\nu_{\mu}$ and $\nu_{\tau}$ observed by the Super-Kamiokande collaboration. For three generations of leptons two classes of such models are found implying: a) $\Delta {m_{23}}^2 \ll \Delta {m_{12}}^2 \approx \Delta {m_{13}}^2 $ and a small mixing between $\nu_{e}$ and the other two neutrinos, b) $\Delta {m_{12}}^2 \ll \Delta {m_{13}}^2 \approx \Delta {m_{23}}^2$ and a nearly maximal mixing for solar neutrino oscillations in vacuum.