Sigma–omega meson coupling and properties of nuclei and nuclear matter

We have constructed a Lagrangian model with a coupling of σ and ω mesons in the relativistic mean-field theory. Properties of finite nuclei and nuclear matter are explored with the new Lagrangian model SIG–OM. The study shows that an excellent description of binding energies and charge radii of nuclei over a large range of isospin is achieved with SIG–OM. With an incompressibility of nuclear matter K=265 MeV, it is also able to describe the breathing-mode isoscalar giant monopole resonance energies appropriately. It is shown that the high-density behaviour of the equation of state of nuclear and neutron matter with the σ–ω coupling is much softer than that of the non-linear scalar coupling model.