Isospin-dependent optical potentials in Dirac-Brueckner-Hartree-Fock approach

Abstract

The relativistic microscopic optical potential (RMOP) is studied within the framework of the Dirac-Brueckner-Hartree-Fock (DBHF) approach. A new decomposition of the Dirac structure of nuclear self-energy in the DBHF is extended to asymmetric nuclear matter calculations. A nucleon effective interaction is introduced to reproduce the results of the G matrix. The real part of nucleon self-energy in asymmetric nuclear matter is calculated with the G matrix in the Hartree-Fock approach, while the imaginary part is obtained from the polarization diagram. Nuclear optical potentials in finite nuclei are derived from the self-energies in asymmetric matter through a local-density approximation. The differential cross sections and the analyzing powers in p+Ca-40 and p+Pb-208 elastic scattering at E-p<= 200 MeV are studied with these RMOPs. A satisfactory agreement with the experimental data is found. This is achieved without readjusting phenomenologically the RMOP derived from the DBHF plus polarization diagram.