Axial-Current Matrix Elements in Light Nuclei from Lattice QCD

TL;DR

This paper reports the first lattice QCD calculations of axial-current matrix elements in light nuclei, which are crucial for improving predictions of nuclear processes and understanding the quenching of the axial coupling constant.

Contribution

It introduces novel lattice QCD computations of multi-nucleon axial-current operators in light nuclei, advancing theoretical nuclear physics.

Findings

First lattice QCD results for axial-current matrix elements in light nuclei

Refined predictions for proton-proton fusion and neutrino-nucleus interactions

Insights into the quenching of the axial coupling constant g_A

Abstract

I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections and $\beta\beta$-decay rates of nuclei. In addition, they are expected to shed light on the phenomenological quenching of $g_A$ that is required in nuclear many-body calculations.