Further explorations of Skyrme–Hartree–Fock–Bogoliubov mass formulas: I: Role of density dependence in pairing force Original Research Article

The HFB-2 mass formula is generalized to make the δ-function pairing force density-dependent. It is shown that the mass data rule out the simple model of a pairing force that vanishes completely in the nuclear interior. Consistency with the mass data is found for a fairly wide range of δ-function pairing forces with a partial weakening in the nuclear interior. In particular, the form of density dependence determined by the realistic nuclear-matter calculations of Garrido et al. is shown to be compatible with the mass data, 2135 measured masses being fitted with an rms error of 0.656 MeV. On this basis we construct a new mass table, HFB-3, running from one drip line to the other. Shell quenching at the neutron-drip line is now somewhat stronger than before, but otherwise the new mass formula does not differ in any conspicuous way from the HFB-2 mass formula.