Nucleons, mesons and deltas in nuclear matter a relativistic Dirac-Brueckner approach

Within the framework of the relativistic Dirac-Brueckner approach properties of both dense and hot symmetric nuclear matter are studied on the basis of a one-boson-exchange interaction. This interaction includes Δ-degrees of freedom with a dynamic description of the Δ-self-energy and reproduces nucleon-nucleon and nucleon-delta experimental observables in the energy range 0–1 GeV. Saturation of nuclear matter is studied and the saturation point is found to lie on a Coester line which goes through the empirical value for nuclear matter. The compressional energy is calculated for densities up to 4 ϱ0 where ϱ0 is the normal nuclear density. Furthermore we have investigated in detail the single-particle interaction in nuclear matter and compared it with other approaches like the non-relativistic imueckner approach and the relativistic impulse approximation. Finally the theory is extended to non-zero temperature by use of finite-temperature Green's functions for dressed nucleons. Isotherms in a P-ϱ diagram are obtained and we study the possible existence of a liquid-vapour phase equilibrium.