Auxiliary field diffusion Monte Carlo calculations of magnetic moments of light nuclei with chiral EFT interactions

TL;DR

This paper uses auxiliary field diffusion Monte Carlo with chiral EFT interactions to accurately compute magnetic moments, energies, and radii of light nuclei, emphasizing the importance of consistent power counting for reliable results.

Contribution

It introduces a systematic approach combining Monte Carlo methods with chiral EFT to calculate nuclear magnetic moments and other properties, highlighting the significance of consistent power counting.

Findings

Good agreement with experimental magnetic moments, energies, and radii.

Consistent power counting is essential for systematic convergence.

Uncertainty analysis shows the impact of chiral expansion truncation.

Abstract

We calculate the magnetic moments of light nuclei ($A < 20$) using the auxiliary field diffusion Monte Carlo method and local two- and three-nucleon forces with electromagnetic currents from chiral effective field theory. For all nuclei under consideration, we also calculate the ground-state energies and charge radii. We generally find a good agreement with experimental values for all of these observables. For the electromagnetic currents, we explore the impact of employing two different power countings, and study theoretical uncertainties stemming from the truncation of the chiral expansion order-by-order for select nuclei within these two approaches. We find that it is crucial to employ consistent power countings for interactions and currents to achieve a systematic order-by-order convergence.