Four-nucleon alpha-type correlations and proton-neutron pairing away from the N = Z line

作者：Sandulescu N^*; Negrea D; Johnson C W

来源：Physical Review C, 2012, 86(4): 041302.

DOI：10.1103/PhysRevC.86.041302

We study the competition between alpha-type and conventional pair condensation in the ground state of nuclei with neutrons and protons interacting via a charge-independent pairing interaction. The ground state is described by a product of two condensates, one of alpha-like quartets and the other one of pairs in excess relative to the isotope with N = Z. It is shown that this ansatz for the ground state gives very accurate pairing correlation energies for nuclei with the valence nucleons above the closed cores O-16, Ca-40, and Sn-100. These results indicate that alpha-type correlations are important not only for the self-conjugate nuclei but also for nuclei away from the N = Z line. In the latter case alpha-like quartets coexist with the collective Cooper pairs formed by the nucleons in excess.

• 出版日期2012-10-15