Density-dependent pairing in nuclei far from stability

Summary

An approach based on the local energy-density functional method for describing the ground-state properties of superfluid nuclei is presented. The generalized variational principle is formulated leading, in the weak pairing approximation, to a set of equations which correspond to a full treatment of the HFB problem with an effective contact pp interaction. The Gor′kov equations for generalized Green’s functions are treated exactly in the coordinate-space representation. The method is used for the combined analysis of differential observables including odd-even mass differences and odd-even effects in charge radii which happen to be very sensitive to the density dependence of the effective pairing force. A better knowledge of this density dependence allows one to make predictions for the pairing gap at the Fermi surface as a function of nuclear matter density.