Isospin splitting of the nucleon-nucleus optical potential

The volume component of the phenomenological optical potential is traced to the microscopic theory of nuclear matter. The latter is based on the Brueckner-Hartree-Fock approach with three-body force, which recently has proved to be able to reproduce the empirical saturation properties of nuclear matter. The self-energy is calculated and its on-shell matrix elements are related to the volume part of the optical potential. A previous investigation, where the real part of the microscopic potential was compared with an empirical one, which is a fit of the experimental nucleon-nucleus elastic scattering, is here extended to the absorptive component. Moreover, the isospin splitting of the optical potential is discussed in connection with the proton and neutron effective masses of isospin asymmetric nuclear systems.