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

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 $|m_{\beta \beta }^{}|\approx 1\mathrm{meV}$. 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.

Comments: 16 pages, 6 figures