Partial-wave contributions to pairing in nuclei

We present a detailed study of partial-wave contributions of nuclear forces to pairing in nuclei. For T = 1, J = 0 pairing, partial waves beyond the standard S-1(0) channel play an interesting role for the pair formation in nuclei. The additional contributions are dominated by the repulsive P-3(1) partial wave. Their effects, and generally spin-triplet nuclear forces between paired nucleons, are influenced by the interplay of spin-orbit partners. We explore the impact of including partial waves beyond the S-1(0) channel on neutron-neutron pairing gaps in semimagic isotopic chains. In addition, we show that nuclear forces favor T = 1, J = 0 over T = 0, J = 1 pairing, except in low-j orbitals. This is in contrast to the free-space motivation that suggests the formation of deuteron-like T = 0 pairs in N = Z nuclei. The suppression of T = 0 pairing is because the S-3(1) strength is distributed on spin-orbit partners and because of the effects of the repulsive P-1(1) channel and of D waves.