Competition between T = 0 and T = 1 pairing in proton-rich nuclei

A cranked mean-field model with two-body T = 1 and T = 0 pairing interactions is presented. Approximate projection onto good particle-number is enforced via an extended Lipkin-Nogami scheme. Our calculations suggest the simultaneous presence of both T = 0 and T = 1 pairing modes in N = Z nuclei. The transitions between different pairing phases are discussed as a function of neutron/proton excess, Tz, and rotational frequency, ħω. The additional binding energy due to the T = 0 np-pairing correlations, is suggested as a possible microscopic explanation of the Wigner energy term in even-even nuclei.