Within the relativistic mean-field approach, we extend the Miyazaki model, where the NN$\sigma$ and NN$\omega$ interactions are modified to suppress the couplings between positive- and negative-energy states of a nucleon in matter. Assuming appropriate density-dependence of the meson-nucleon couplings, we study nuclear matter and finite nuclei. The model can reproduce the observed properties of $^{ 16}$O and $^{ 40}$Ca well. We also examine if the model is natural.
Categories: nucl-th