The relativistic G-matrix approach and applications

The Dirac-Brueckner approach to the nuclear many-body problem is described. A family of relativistic mesonexchange potentials is used which apply the pseudovector coupling for the interaction of pseudoscalar mesons ( , ) with nucleons. These potentials describe low-energy two-nucleon scattering and the deuteron data accurately. Using these potentials, the properties of nuclear matter are calculated in the Dirac-Bueckner-Hartree-Fock approximation, in which the empirical nuclear matter saturation is explained quantitatively. Size and nature of relativistic effects included in the present approach are examined in detail. Furthermore the relativistic density-dependent Hartree approximation is applied for finite nuclei, where the coupling constants of the relativistic Hartree-Lagrangian are made density dependent and are obtained from the relativistic Brueckner-Hartree-Fock results of nuclear matter. The calculated results on binding energies and root mean square radii of O and Ca agree well with experiment. The charge densities from electron scattering are also calculated and their dependence on the nucleon-nucleon interaction is discussed in relation with nuclear matter properties.