Towards the meV limit of the effective neutrino mass in neutrinoless double-beta decays

TL;DR

This paper discusses the importance and implications of future neutrinoless double-beta decay experiments reaching a sensitivity of about 1 meV for the effective neutrino mass, exploring the resulting constraints on neutrino properties.

Contribution

It provides a detailed analysis of the potential constraints on neutrino mass and CP-violating phases assuming such experimental sensitivity and improved oscillation data.

Findings

Constraints on lightest neutrino mass and CP phases are derived.

Implications for neutrino mass spectrum and cosmological parameters are discussed.

Highlights the significance of achieving 1 meV sensitivity in future experiments.

Abstract

In this paper, we emphasize why it is important for future neutrinoless double-beta ($0\nu\beta\beta$) decay experiments to reach the sensitivity to the effective neutrino mass $|m^{}_{\beta\beta}| \approx 1~{\rm meV}$. Assuming such a sensitivity and the precisions on neutrino oscillation parameters after the JUNO experiment, we fully explore the constrained regions of the lightest neutrino mass $m^{}_1$ and two Majorana-type CP-violating phases $\{\rho, \sigma\}$. The implications for the neutrino mass spectrum, the effective neutrino mass $m^{}_\beta$ in beta decays and the sum of three neutrino masses $\Sigma \equiv m^{}_1 + m^{}_2 + m^{}_3$ relevant for cosmological observations are also discussed.