Phase transition between the isovector to isoscalar pairing correlations in deformed N = Z nuclei

Abstract

Abstract We investigate the pairing correlations on N = Z nuclei. In particular, the isoscalar (IS) pairing mode in neutron-proton (np) pairing is discussed in detail because the IS np pairing is closely related to the tensor force in the nucleon-nucleon interaction. Recent experiments demonstrated that the IS pairing might be enhanced from the M1 spin strength distribution data and deuteron, which is a consequence of the IS pairing, can be detected in 16O(p,p’d)14N reaction. The present study illustrates that the IS np pairing can be condensed not only in S=0, L = odd states but also in S=1, L=even states. The former is usually treated as T=0 np pairing. The latter is associated with deuteron and has not been fully treated in the BCS theory for the nuclear structure. In particular, the latter np pairing can be ejected as deuteron from the energetic probes in the experiments. Detailed analyses of the np pairing are performed mainly on 16O and extended to other N = Z nuclei.