Magnetic properties of light nuclei from lattice QCD

TL;DR

This paper reviews lattice QCD methods and presents recent calculations of magnetic properties of light nuclei and nucleons at heavier pion masses, showing consistency with experimental magnetic moments and cross sections.

Contribution

It provides new lattice QCD results on magnetic moments, cross sections, and polarizabilities of light nuclei at pion masses of 805 MeV and 450 MeV, including the first such calculations.

Findings

Magnetic moments align with experimental values in natural nuclear magnetons.

Calculated low-energy np→dγ cross section agrees with experiment.

Large isovector polarizability observed for the nucleon at heavier pion masses.

Abstract

After a short review of Lattice QCD methodology and techniques, I summarize recent results of Lattice QCD calculations of the interactions of nucleons and light nuclei with magnetic fields at pion masses of 805 MeV and 450 MeV. Interestingly, the magnetic moments are found to be consistent with the experimental values when given in terms of natural nuclear magnetons. The very low-energy cross section for $np\rightarrow d\gamma$ is calculated and found to agree with the experimental measurement. First calculations of the magnetic polarizabilities of light nuclei are presented, with a large isovector polarizability observed for the nucleon at these heavier pion masses.