Effects of Three-Nucleon Forces and Two-Body Currents on Gamow-Teller Strengths

We optimize chiral interactions at next-to-next-to leading order to observables in two- and three-nucleon systems and compute Gamow-Teller transitions in C14 and O22,24 using consistent two-body currents. We compute spectra of the daughter nuclei N14 and F22,24 via an isospin-breaking coupled-cluster technique, with several predictions. The two-body currents reduce the Ikeda sum rule, corresponding to a quenching factor q2≈0.84–0.92 of the axial-vector coupling. The half-life of C14 depends on the energy of the first excited 1+ state, the three-nucleon force, and the two-body current.