Neutrinoless Double Beta Decay in the Presence of Light Sterile Neutrinos

TL;DR

This paper explores how light sterile neutrinos could influence neutrinoless double beta decay predictions, identifying parameter regions where the decay signal might be suppressed or detectable in upcoming experiments.

Contribution

It provides a detailed analysis of the impact of 3+1 and 3+2 sterile neutrino schemes on neutrinoless double beta decay effective mass predictions, including conditions for suppression.

Findings

Suppression of effective Majorana mass due to parameter cancellations.

Identification of parameter regions with detectable decay signals.

Implications for next-generation neutrinoless double beta decay experiments.

Abstract

We investigate the predictions for neutrinoless double beta ($(\beta \beta)_{0 \nu}$-) decay effective Majorana mass $\left| \langle \, m \, \rangle \right|$ in the 3+1 and 3+2 schemes with one and two additional sterile neutrinos with masses at the eV scale. The two schemes are suggested by the neutrino oscillation interpretation of the reactor neutrino and Gallium "anomalies" and of the data of the LSND and MiniBooNE experiments. We analyse in detail the possibility of a complete or partial cancellation between the different terms in $\left| \langle \, m \, \rangle \right|$, leading to a strong suppression of $\left| \langle \, m \, \rangle \right|$. We determine the regions of the relevant parameter spaces where such a suppression can occure. This allows us to derive the conditions under which the effective Majorana mass satisfies $\left| \langle \, m \, \rangle \right| > 0.01$ eV, which is the range planned to be exploited by the next generation of $(\beta \beta)_{0 \nu}$-experiments.