Constraining Neutrinoless Double-Beta Decay Matrix Elements from Ab Initio Nuclear Theory

TL;DR

This paper uses ab initio nuclear theory to analyze and constrain the nuclear matrix elements relevant for neutrinoless double-beta decay, aiming to reduce uncertainties and improve experimental sensitivity.

Contribution

It applies the valence-space in medium similarity renormalization group to study correlations and interaction dependence of decay matrix elements from first principles.

Findings

Correlations identified between decay matrix elements and other observables.

Uncertainty constraints derived from multiple chiral interactions.

Interaction dependence of nuclear matrix elements analyzed.

Abstract

As experimental searches for neutrinoless double-beta ($0\nu\beta\beta$) decay are entering a new generation, with hopes to completely probe the inverted mass hierarchy, the need for reliable nuclear matrix elements, which govern the rate of this decay, is stronger than ever. Since a large discrepancy in results is typically found with nuclear modela, a large unknown still exists on the sensitivity of these experiments to the effective neutrino mass. We consider this problem from a first-principles perspective, using the ab initio valence-space in medium similarity renormalization group. In particular, we study correlations of the $0\nu\beta\beta$-decay matrix elements in $^{76}$Ge with other observables, such as the double Gamow-Teller giant resonance, from 34 input chiral interactions in an attempt to constrain our uncertainties and investigate the interaction dependence of the nuclear matrix element.