Author:

Keywords:

Science & Technology, Physical Sciences, Physics, Nuclear, Physics, VACUUM POLARIZATION, SHELL EVOLUTION, NEUTRON-STAR, MATTER, DENSITY, MESON, MASS, SCATTERING, HOT, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 5106 Nuclear and plasma physics

Abstract:

In order to predict properties of asymmetric nuclear matter, we construct a relativistic mean field (RMF) model consisting of one-meson exchange (OME) terms and point coupling (PC) terms. In order to determine the density dependent parameters of this model, we use properties of isospin symmetric nuclear matter in combination with theinformationonnucleon-nucleonscatteringdata,whicharegivenintheformofthedensitydependentG-matrix derived from Brueckner calculations based on the Tamagaki potential. We show that the medium- and long-range components of this G-matrix can be described reasonably well by our effective OME interaction. In order to take into account the short-range part of the nucleon-nucleon interaction, which cannot be described well in this manner, a point coupling term is added. Its analytical form is taken from a model based on chiral perturbation theory. It contains only one additional parameter, which does not depend on the density. It is, together with the parameters of the OME potentials adjusted to the equation of state of symmetric nuclear matter. We apply this model for the investigation of asymmetric nuclear matter and find that the results for the symmetry energy as well as for the equation of state of pure neutron matter are in good agreement with either experimental data or with presently adopted theoretical predictions. In order to test the model at higher density, we use its equation of state for an investigation of properties of neutron stars.