Magnetic Moments of A=3 Nuclei Obtained from Chiral Effective Field Theory Operators

Chiral effective field theory (xEFT) provides a framework for obtaining internucleon interactions in a systematically improvable fashion from first principles, while also providing for the derivation of consistent electroweak current operators. In this work, we apply consistently derived interactions and currents towards calculating the magnetic dipole moments of the A = 3 systems 3H and 3He. We focus here on LENPIC interactions obtained using semilocal coordinate-space (SCS) regularization. Starting from the momentum-space representation of the LENPIC xEFT vector current, we derive the SCS-regularized magnetic dipole operator up through next-to-next-to-leading order (N2LO). We then carry out no-core shell-model calculations for 3H and 3He systems using the SCS LENPIC interaction at N2LO in xEFT and evaluate the magnetic dipole moments obtained using the consistently derived one-nucleon and two-nucleon electromagnetic currents. As anticipated by prior results with xEFT currents, the current corrections through N2LO provide improved, but not yet complete, agreement with experiment for the 3H and 3He magnetic dipole moments.