On relativistic effects in the low-energy spectra of nuclei

The low energy spectra of some 1sOd-shell nuclei are investigated by shell model calculations employing a recent relativistic meson-exchange potential. The interaction is renormalized in a conventional way to account for correlations, which are not contained in the shell-model basis. Special attention is paid to the influence of relativistic medium effects on the calculated spectra. We find that these effects are small and do not spoil the agreement with the experimental data. This finding together with the fact of a quantitative description of ground-state properties of the three-nucleon system and of nuclear matter, using the same NN interaction, can be understood as an indication that modern relativistic meson-exchange potentials may allow for a more consistent explanation of nuclear structure than traditional nuclear force models. (orig.)