Towards Precise and Accurate Calculations of Neutrinoless Double-Beta Decay: Project Scoping Workshop Report

TL;DR

This workshop report reviews progress and outlines a comprehensive plan to improve the accuracy and precision of nuclear matrix element calculations for neutrinoless double-beta decay, crucial for interpreting experimental results.

Contribution

It presents a detailed road map integrating effective field theory, lattice QCD, and nuclear-structure theory to enhance calculation accuracy and uncertainty quantification.

Findings

Progress in effective field theory, lattice QCD, and ab initio methods.

Development of a Bayesian uncertainty quantification plan.

A comprehensive roadmap for future theoretical and computational work.

Abstract

We present the results of a National Science Foundation (NSF) Project Scoping Workshop, the purpose of which was to assess the current status of calculations for the nuclear matrix elements governing neutrinoless double-beta decay and determine if more work on them is required. After reviewing important recent progress in the application of effective field theory, lattice quantum chromodynamics, and ab initio nuclear-structure theory to double-beta decay, we discuss the state of the art in nuclear-physics uncertainty quantification and then construct a road map for work in all these areas to fully complement the increasingly sensitive experiments in operation and under development. The road map contains specific projects in theoretical and computational physics as well as an uncertainty-quantification plan that employs Bayesian Model Mixing and an analysis of correlations between double-beta-decay rates and other observables. The goal of this program is a set of accurate and precise matrix elements, in all nuclei of interest to experimentalists, delivered together with carefully assessed uncertainties. Such calculations will allow crisp conclusions from the observation or non-observation of neutrinoless double-beta decay, no matter what new physics is at play.