NEUTRON-STARS AND NUCLEI IN THE MODIFIED RELATIVISTIC HARTREE APPROXIMATION

We have examined the properties of neutron-rich matter and finite nuclei in the modified relativistic Hartree approximation for several values of the renormalization parameter, mu, around the standard choice of mu equal to the nucleon mass M. Observed neutron-star masses do not effectively constrain the value of mu. However, for finite nuclei the value mu/M = 0.79, suggested by nuclear matter data, provides a good account of the bulk properties with a sigma mass of about 600 MeV. This value of mu/M renders the effective three- and four-body scalar self-couplings to be zero at 60% of equilibrium nuclear matter density. We have also found that the matter part of the exchange diagram has little impact on the bulk properties of neutron stars.