Influence of the effective interaction on spectra of superfluid nuclei, ch. 6

An attempt was made to improve the description of the collective 2+ and 3- states in even single-closed-shell nuclei by using a 'realistic' effective interaction based on the Reid soft core potential instead of the Gaussian forces which are commonly used. As an example, the Sn isotopes are considered. The results of the Reid force are no better than those of the Gaussian. The too large excitation-energies of the collective 2+ and 3- states found earlier are apparently not due to particular features of the Gaussian effective forces used. Explicit admixture of a quadrupole and an octupole part in the effective interaction does improve the description of the collective 2+ and 3- states, but it makes the description of the other excited states worse