5 Density Dependent Relativistic Field Theory

Abstract

The density-dependent relativistic hadron (DDRH) field theory is the prototype of a theory with interaction vertices having an intrinsic functional structure. In order to conserve important fundamental principles, including Lorentz-invariance, covariance of the field equations and thermodynamical consistency, the functional form must be chosen in terms of Lorentz-scalar combinations of field operators. In DDRH theory the functional form of the vertices is determined theoretically from in-medium Dirac-Brueckner interactions, obtained from the realistic Bonn and Groningen free-space NN interactions. The density dependence of the vertices is obtained in infinite nuclear matter by mapping the self-consistent DBHF self-energies to the corresponding DDRH expressions.

Applications to stable and exotic nuclei off the valley of stability are presented. A clear advantage of the microscopic approach is that it allows to extend the calculations at safe grounds into the regions far off stability. The agreement with experimental data is very satisfactory. The DDRH approach is easily extended to the full SU(3) flavor multiplet, including also the Λ, Σ and Ξ baryons. Results for β-stable neutron matter and the mass-radius relation for neutron stars are discussed.