A study of the scenario with nearly degenerate Majorana neutrinos

TL;DR

This paper explores a neutrino mass scenario where three Majorana neutrinos have nearly equal masses in the eV range, analyzing constraints and experimental tests relevant to this model.

Contribution

It provides a detailed analysis of a nearly degenerate Majorana neutrino mass scenario considering multiple experimental constraints.

Findings

Constraints favor a specific pattern of neutrino masses and mixing angles.

The scenario is consistent with current direct search and neutrinoless double beta decay limits.

Experimental tests can further validate or exclude this neutrino mass pattern.

Abstract

Motivated by cosmological considerations, and by the atmospheric and solar neutrino flux deficits, we consider the scenario in which the three Standard Model neutrinos are endowed with a nearly equal Majorana mass in the eV range. Combined constraints coming from (1) direct search for electron neutrino mass, (2) absence of neutrinoless double beta decay, and (3) unsuppressed electron neutrino flux in present reactor experiments, imply a quite well specified pattern of neutrino masses and mixing angles. We discuss the experimental tests of the model and comment on the features of this scenario.