Pairing-plus-quadrupole-plus-octupole model

The conventional pairing-plus-quadrupole model was augmented with the octupole-octupole interaction. The symmetries of the HF mean field are discussed. It is shown that under the assumption of the S-symmetry of the HF mean field, only 2 quadrupole and 2 octupole parameters have non-zero expectation values in the HFB ground state. A detailed analysis of 2 possible approaches to the HFB treatment of the model Hamiltonian is presented. 2 tabs., 13 refs