Influence of Density-Dependent Coupling Constants on Equation of State of Infinite Symmetric Nuclear Matter

In the mean field approximation of nonlinear relativistic σ—ω—ρ model, we have studied the influence of density-dependent coupling constants between nucleons and mesons on the equation of state (EOS) of infinite symmetric nuclear matter in different conditions. We find that the EOS of nuclear matter will become stiffer as c, d in the self-interaction of σ meson increase when the coefficients except a_ω in Γ_ω, in which the opposite occurs, are fixed. On the other hand, greater values of a_σ, b_σ, c_σ, a_ω, d_ω and smaller values of d_σ, b_ω, c_ω will lead to stiffer EOS if c and d are fixed. Besides, greater values of Γ_σ,ω lead to stiffer EOS in high density region for the EOS with same incompressibility coefficient at saturation density. (paper)