Quantum Monte Carlo calculations of electromagnetic moments and transitions in A <= 9 nuclei with meson-exchange currents derived from chiral effective field theory

TL;DR

This paper presents Quantum Monte Carlo calculations of electromagnetic properties in light nuclei, incorporating meson-exchange currents from chiral effective field theory, achieving excellent agreement with experimental data.

Contribution

It introduces a novel implementation of meson-exchange currents derived from chiral effective field theory into Quantum Monte Carlo calculations for light nuclei.

Findings

Two-body meson-exchange currents significantly improve agreement with experimental magnetic moments.

MEC contributions account for up to 20-40% of magnetic moments in A=9 nuclei.

Chiral EFT-based MEC operators provide a consistent framework for nuclear electromagnetic calculations.

Abstract

Quantum Monte Carlo calculations of electromagnetic moments and transitions are reported for A <= 9 nuclei. The realistic Argonne v18 two-nucleon and Illinois-7 three-nucleon potentials are used to generate the nuclear wave functions. Contributions of two-body meson-exchange current (MEC) operators are included for magnetic moments and M1 transitions. The MEC operators have been derived in both a standard nuclear physics approach and a chiral effective field theory formulation with pions and nucleons including up to one-loop corrections. The two-body MEC contributions provide significant corrections and lead to very good agreement with experiment. Their effect is particularly pronounced in the A=9, T=3/2 systems, in which they provide up to 20% (40 %) of the total predicted value for the 9Li (9C) magnetic moment.