HFB in a restricted space

Abstract

A restricted Hartree-Fock-Bogoliubov method is developed with a restriction on the angular momenta of the Cooper pairs that conform the vacuum (SD or SDG). The method is applied to 176Yb. The quadrupole moment in the SD subspace is found to be 80% for neutrons and 91% for protons of its value in the full space. The inclusion of the G part of the Cooper pairs improves that agreement. The descriptions in terms of boson condensate and coherent states are discussed.