The nature of massive neutrinos and multiple mechanisms in neutrinoless double beta decay

TL;DR

This paper explores how multi-isotope measurements can help determine the nature of neutrinos and identify mechanisms behind neutrinoless double beta decay, focusing on data combination strategies across different nuclei.

Contribution

It proposes a multi-isotope approach to extract information on decay mechanisms and discriminate between different theoretical models of neutrinoless double beta decay.

Findings

Multi-isotope data can help distinguish decay mechanisms.

Combining data from nuclei with different nuclear matrix elements is effective.

The approach can identify non-interfering and interfering mechanisms.

Abstract

Determining the nature -Dirac or Majorana- of massive neutrinos is one of the most pressing and challenging problems in the field of neutrino physics. We discuss how one can possibly extract information on the couplings, if any, which might be involved in neutrinoless double beta-decay using a multi-isotope approach. We investigate as well the potential of combining data on the half-lives of nuclides which largely different Nuclear Matrix Elements such as $^{136}$Xe and of one or more of the four nuclei $^{76}$Ge, $^{82}$Se, $^{100}$Mo and $^{130}$Te, for discriminating between different pairs of non-interfering or interfering mechanisms of neutrinoless double beta-decay. The case studies do not extend to the evaluation of the theoretical uncertainties of the results, due to the nuclear matrix elements calculations and other causes.