Nuclear masses, shell-model and superheavy nuclei (II)

Abstract

In the first paper in this series two forms of effective ( K-matrix) interaction were used in self-consistent field calculations on some closed-shell nuclei. Both were velocity dependent to simulate the Serber character of the force. One of them, which defined model A, did not depend explicitly on the nuclear medium. The second, model B, contained a density-dependent shortranged repulsion of the same strength for both n-n and n-p interactions. In this paper the effect of the tensor force is approximated by allowing the n-p interaction to be density dependent. This defines model C. In model D the effect of the binding on the twobody interaction (dispersion effect) is included approximately. Both models C and D give a spectacular improvement in single-particle spectra over the previous models. The contribution of the second-order rearrangement to the energies of hole states in 208Pb is estimated from calculations for nuclear matter. It is found to increase the agreement with the experimental spectrum. In 298114 the proton f 7 2 − f 5 2 splitting is 2.7 MeV for both models C and D, but the (occupied) i 13 2 level is located between the f-levels, so that the gap at Z = 114 is reduced to 1.9 and 1.1 MeV in models C and D, respectively. The gap at N = 184 is 2.3 and 2.5 MeV, respectively.