GFMC calculations of electromagnetic moments and M1 transitions in $A\leq 9$ nuclei

TL;DR

This paper uses Green's function Monte Carlo methods to calculate electromagnetic moments and M1 transitions in nuclei with mass number up to 9, emphasizing the importance of two-body meson-exchange currents for accurate results.

Contribution

It introduces detailed two-body meson-exchange current corrections in GFMC calculations, significantly improving agreement with experimental data for light nuclei.

Findings

Two-body effects significantly correct magnetic moments and M1 transitions.

Corrections are especially large in A=9, T=3/2 nuclei.

Two-body currents account for up to 20-40% of magnetic moments.

Abstract

We present recent Green's function Monte Carlo calculations of magnetic moments and M1 transitions in $A \leq 9$ nuclei, which include corrections arising from two-body meson-exchange electromagnetic currents. Two-body effects provide significant corrections to the calculated observables, bringing them in excellent agreement with the experimental data. In particular, we find that two-body corrections are especially large in the A=9, $T=3/2$ systems, in which they account for up to $\sim 20%$ ($\sim 40 %$) of the total predicted value for the $^9$Li ($^9$C) magnetic moment.