Choice of the density-dependent effective interaction and alpha decay of heavy spherical nuclei

The parameters of density-dependent effective interaction are studied for some nuclei in the vicinity of a 208Pb double-magic nucleus. Both nuclei having two nucleons (holes) over magic core and some superfluid nuclei are considered. It is found that the magnitudes of the matrix elements for the zero-range forces (delta forces) are more than three times larger in comparison with the case of the finite-range forces (f forces). Sets of parameters for the effective interaction, which does not lead to the superfluidity of nuclear matter are obtained. Besides, these parameters depend weakly on mass number. It is shown that the attractive part of interaction is substantially larger for the case of f forces than for the delta forces. The theoretical enhancement coefficients for the favoured α decay of 210Po, 210Pb and 224Th nuclei are calculated. For the case of f forces a tendency to saturation of the enhancement coefficients with the increase of the shell-model basis is found