E.E. Saperstein

Microscopic study of the effective pairing interaction in semi-infinite nuclear matter with the separable NN-interaction

Abstract The problem of pairing in semi-infinite nuclear matter is considered microscopically. Equations for the effective pairing interaction in the semi-infinite matter for the separable form of the NN -interaction are derived and solved directly, without use of any form of local approximation. Numerical solution is carried out for a separable representation of the Paris NN -potential. A version of the local approximation, the “local potential approximation”, is suggested which works sufficiently well even in the surface region. The effective pairing interaction obtained in our calculations reveals a strong variation in the surface region changing from a strong attraction outside the nuclear matter to almost zero value inside. Thus, it confirms the idea of the surface nature of nuclear pairing.

Existence of nuclei with unusual neutron excess

Abstract A realistic model is suggested based on the quasiparticle Lagrange version of the self-consistent Finite Fermi Systems theory supplemented with the microscopically calculated surface parameters of the Landau–Migdal interaction amplitude. The latter are expressed in terms of the off-shell T -matrix of free NN -scattering and show a strong dependence on the chemical potential of a nucleus under consideration in the drip line vicinity. This effect could result in shifting the neutron drip line position to very large values of the neutron excess.

Surface behaviour of the pairing gap in a slab of nuclear matter

Abstract.The surface behavior of the pairing gap previously studied for semi-infinite nuclear matter is analyzed in the slab geometry. The gap-shape function is calculated in two cases: a) pairing with the Gogny force in a hard-wall potential and b) pairing with the separable Paris interaction in a Saxon-Woods mean-field potential. It is shown that the surface features are preserved in the case of slab geometry, being almost independent of the width of the slab. It is also demonstrated that the surface enhancement is strengthened as the absolute value of chemical potential

Surface behaviour of the pairing gap in semi-infinite nuclear matter

\vert\mu\vert

On the Brueckner theory of pairing in semi-infinite nuclear matter beyond the local density approximation

decreases which simulates the approach to the nucleon drip line.-1

On the surface parameters of the Landau-Migdal amplitude

The

A simple model for the microscopic effective pairing interaction

^1S_0

METHOD OF CALCULATING LOW-LYING SPECTRA IN SPHERICAL NUCLEI.

-pairing gap in semi-infinite nuclear matter is evaluated microscopically using the effective pairing interaction recently found explicitly in the coordinate representation starting from the separable form of the Paris NN-potential. Instead of direct iterative solution of the gap equation, a new method proposed by V.A.Khodel, V.V.Khodel and J.W.Clark was used which simplifies the procedure significantly. The gap

Effects of proximity to the pion condensation threshold in inelastic nucleon-nucleus scattering with excitation of unnatural-parity states

\Delta

The long-range part of the effective interaction between quasiparticles in nuclei

obtained in our calculations exibits a strong variation in the surface region with a pronounced maximum near the surface.Abstract The 1 S 0 -pairing gap in semi-infinite nuclear matter is evaluated microscopically using the effective pairing interaction recently derived in the coordinate representation from a separable form of the Paris NN -potential. Instead of a direct iterative solution of the gap equation, a new method proposed by V. A. Khodel, V. V. Khodel and J. W. Clark was used which simplifies the procedure significantly. The gap Δ obtained in our calculations exhibits a strong variation in the surface region with a pronounced maximum near the surface.