Relativistic Hartree–Bogoliubov theory and the isospin dependence of the effective nuclear force

The role of the isospin dependence of the effective Lagrangian of the Relativistic Mean Field Theory (RMF) is investigated. The standard RMF density functional based on non-linear meson-exchange terms is extended to include density dependent meson–nucleon coupling constants. The new variation of the RMF, in which the isospin dependence enters in both isoscalar and isovector channels, provides improved description of the equation of state of neutron matter, better isovector properties of finite nuclei such as neutron skin thickness, more accurate nuclear masses and a consistent description of both isovector and isoscalar giant resonances.