Determination of neutrino mass ordering in future ${}^{76}$Ge-based neutrinoless double-beta decay experiments

Abstract

Motivated by recent intensive experimental efforts on searching for neutrinoless double-beta decays, we perform a detailed analysis of the physics potential of the experiments based on ${}^{76}\mathrm{Ge}$. Assuming no signals, current and future experiments could place a $90\%$ lower limit on the half life $T_{1/2}^{0\nu }\gtrsim 4\times 10^{26}\mathrm{yr}$ and $T_{1/2}^{0\nu }\gtrsim 7\times 10^{27}\mathrm{yr}$, respectively. Then, how to report an evidence for neutrinoless double-beta decays is addressed by following the Bayesian statistical approach. For the first time, we present a quantitative description of experimental power to distinguish between normal and inverted neutrino mass orderings. Taking an exposure of $10^4\mathrm{kg}\cdot \mathrm{yr}$ and a background rate of $10^{-4}\mathrm{counts}/(\mathrm{keV}\cdot \mathrm{kg}\cdot \mathrm{yr})$, we find that a moderate evidence for normal neutrino mass ordering (i.e., with a Bayes factor $\mathcal{B}$ given by $\ln (\mathcal{B})\simeq 2.5$ or a probability about $92.3\%$ according to the Jeffreys scale) can be achieved if the true value of effective neutrino mass $m_{\beta \beta }^{}$ turns out to be below $0.01\mathrm{eV}$.

16 pages, 7 figures, the Jeffreys scale used, more discussions added, to appear in Phys. Rev. D

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Cited by in corpus (8)

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• Impact of an eV-mass sterile neutrino on the neutrinoless double-beta decays: a Bayesian analysis
• Half-life Expectations for Neutrinoless Double Beta Decay in Standard and Non-Standard Scenarios
• Tentative sensitivity of future $0\nu \beta \beta$-decay experiments to neutrino masses and Majorana CP phases
• Inference of neutrino nature and Majorana CP phases from $0\nu \beta \beta$ decays with inverted mass ordering
• Neutrino Mass Ordering in Future Neutrinoless Double Beta Decay Experiments