Effect of Fock terms on nuclear symmetry energy based on Lorentz-covariant decomposition of nucleon self-energies

Abstract

Abstract Using the Lorentz-covariant decomposition of nucleon self-energies with relativistic mean-field approximation, we study the effect of Fock terms on the density dependence of nuclear symmetry energy, E sym. It is found that the Fock contribution suppresses the potential part of E sym at higher densities, and the constraint from the heavy-ion collision data is in favor of the present result including exchange terms with the cutoff parameters given by the CD-Bonn potential. In addition, not only the isovector-vector (ρ) meson but also the isoscalar (σ, ω) and π mesons give influence on the potential part of E sym through the exchange diagram.