The search for neutrinoless double beta decay

TL;DR

The paper reviews the progress and significance of searching for neutrinoless double beta decay, highlighting recent experimental efforts, theoretical advancements, and its implications for understanding neutrino properties and mass origin.

Contribution

It provides a comprehensive overview of current experimental techniques, recent progress in nuclear matrix element calculations, and the potential impact on particle physics and neutrino mass theories.

Findings

Progress in experimental detection techniques

Advances in nuclear matrix element calculations

Potential for near-future observation

Abstract

In the last two decades the search for neutrinoless double beta decay has evolved into one of the highest priorities for understanding neutrinos and the origin of mass. The main reason for this paradigm shift has been the discovery of neutrino oscillations, which clearly established the existence of massive neutrinos. An additional motivation for conducting such searches comes from the existence of an unconfirmed, but not refuted, claim of evidence for neutrinoless double decay in $^{76}\text{Ge}$. As a consequence, a new generation of experiments, employing different detection techniques and $\beta\beta$ isotopes, is being actively promoted by experimental groups across the world. In addition, nuclear theorists are making remarkable progress in the calculation of the neutrinoless double beta decay nuclear matrix elements, thus eliminating a substantial part of the theoretical uncertainties affecting the particle physics interpretation of this process. In this report, we review the main aspects of the double beta decay process and some of the most relevant experiments. The picture that emerges is one where searching for neutrinoless double beta decay is recognized to have both far-reaching theoretical implications and promising prospects for experimental observation in the near future.