Influence of Density-Dependent Coupling Constants on Symmetry Energy of Nuclear Matter

In the mean field approximation of nonlinear relativistic σ − ω − ρ model, we study the influence of the density-dependent coupling constants, between nucleons and mesons on the symmetry energy S (ρ ) of infinite nuclear B matter, in four different density-dependent formalism. We find greater Γ and L when Γ leads to greater K , c and ρ σ ,ω sym d are fixed and indicate larger S (ρ ) in high density region. In addition, the density dependence of Γ make S (ρ ) σ ,ω ,ρ B B smaller in high density region, and they make K and L more sensitive to the changing of parameters at different sym density.