Mean-field effects on collective flow in high-energy heavy-ion collisions at 2–158<i>A</i>GeV energies

Abstract

Collective flows in heavy-ion collisions from AGS [$(2--11)A$ GeV] to SPS [$(40,158)A$ GeV] energies are investigated in a nonequilibrium transport model with the nuclear mean field (MF). Sideward $\ensuremath{\langle}{p}_{x}\ensuremath{\rangle}$, directed ${v}_{1}$, and elliptic flows ${v}_{2}$ are systematically studied with different assumptions for the nuclear equation of state (EOS). We find that the momentum dependence on the nuclear MF is important for the understanding of the proton collective flows at AGS and SPS energies. Calculated results with momentum-dependent MF qualitatively reproduce the experimental data of proton sideward, directed, and elliptic flows in a incident energy range of $(2--158)A$ GeV.