Quantum Monte Carlo calculations of magnetic moments and M1 transitions in A≤7 nuclei including meson-exchange currents

Green's function Monte Carlo calculations of magnetic moments and $M1$ transitions including two-body meson-exchange current (MEC) contributions are reported for $$A\leq7$$ nuclei. The realistic Argonne $$v_{18}$$ two-nucleon and Illinois-2 three-nucleon potentials are used to generate the nuclear wave functions. The two-body meson-exchange operators are constructed to satisfy the continuity equation with the Argonne $$v_{18}$$ potential. The MEC contributions increase the $A$$=3,7 isovector magnetic moments by 16\% and the $$A$=6,7 transition rates by 17--34\%, bringing them into very good agreement with the experimental data.