Neutrinoless double-beta decay and seesaw mechanism

TL;DR

This paper discusses how neutrinoless double-beta decay, if observed, can provide insights into the seesaw mechanism of neutrino mass generation, especially under the inverted hierarchy scenario, by comparing experimental data with theoretical predictions.

Contribution

It derives allowed half-life ranges for neutrinoless double-beta decay in the inverted hierarchy and discusses implications for the seesaw mechanism and future experiments.

Findings

Allowed half-life ranges for neutrinoless double-beta decay are derived.

The role of nuclear matrix elements in decay rate predictions is analyzed.

Future observations could test the standard seesaw mechanism assumptions.

Abstract

From the standard seesaw mechanism of neutrino mass generation, which is based on the assumption that the lepton number is violated at a large (~10exp(+15) GeV) scale, follows that the neutrinoless double-beta decay is ruled by the Majorana neutrino mass mechanism. Within this notion, for the inverted neutrino-mass hierarchy we derive allowed ranges of half-lives of the neutrinoless double-beta decay for nuclei of experimental interest with different sets of nuclear matrix elements. The present-day results of the calculation of the neutrinoless double-beta decay nuclear matrix elements are briefly discussed. We argue that if neutrinoless double-beta decay will be observed in future experiments sensitive to the effective Majorana mass in the inverted mass hierarchy region, a comparison of the derived ranges with measured half-lives will allow us to probe the standard seesaw mechanism assuming that future cosmological data will establish the sum of neutrino masses to be about 0.2 eV.