Standard and quasideuteron pairing in asymmetric nuclear matter

We study the standard 1S0 and the quasideuteron 3S1−3D1 pairing fields in asymmetric nuclear matter, using a Bonn meson-exchange interaction in a Dirac-Hartree-Fock-Bogoliubov approximation. As in earlier calculations, the standard pairing fields fall to zero at densities below saturation, due to relativistic effects. We obtain a quasideuteron field very similar to those found in nonrelativistic calculations at densities below saturation, both in symmetric and asymmetric nuclear matter. This field has the properties of a Bose-Einstein condensate at low densities and those of a BCS condensate at high densities. The quasideuteron pairing field in asymmetric nuclear matter is stable only when accompanied by standard 1S0 neutron-neutron and proton-proton pairing fields that are different from the fields obtained when the quasideuteron field is zero. The coupled pairing field configuration is the nuclear matter ground state.