CAN THE EQUATION OF STATE OF ASYMMETRIC NUCLEAR-MATTER BE STUDIED USING UNSTABLE NUCLEI

This paper shows that nuclear radii and neutron skins do directly refl ect the saturation density of asymmetric nuclear matter. The proton di stributions in a nucleus have been found to be remarkably independent of the equation of state (EOS) of the asymmetric matter. It is the neu tron distributions that are dependent on the EOS. Macroscopic model ca lculations have been performed over the entire range of the nuclear ch art based on two popular phenomenological, but distinctively different , EOS: the SIII parameter set for the non-relativistic Skyrme Hartree- Fock theory and the TMI parameter set in the relativistic mean field t heory, The saturation density for a small proton fraction remains almo st the same as the normal nuclear matter density for SIII EOS, but it becomes significantly small for the TMI EOS. The key EOS parameters us ed to describe the saturation density are the density derivative of th e symmetry energy and the incompressibility of symmetric nuclear matte r, while the saturation energy is written using the symmetry energy al one as a good approximation. We conclude that a systematic experimenta l study of heavy unstable nuclei would enable us to determine the EOS of asymmetric nuclear matter at about the normal nuclear matter densit y with a fixed proton fraction down to about 0.3. (C) 1998 Elsevier Sc ience B.V.