The effect of the nuclear equation of state on the direct flow in heavy ion collision reaction by using quantum molecular dynamics model

This work concentrated on the effect of the nuclear equation of state on the direct flow (v(1)) in heavy ion collision reaction by using the quantum molecular dynamics (QMD) model. In addition, the proton direct flow is a function of the centrality transverse component of the 4-velocity (u(t0)) at incident energy 0.09 A GeV and impact parameter between 0.25 and 0.45 fm by using the nuclear equation of state (soft and hard EoS), computed and compared with FOPI experiments. The calculated results show that the proton direct flow as a function of u(t0) is dependent appreciably upon the nuclear equation of state (EoS). The proton direct flow as a function of u(t0) is calculated with soft EoS that is consistent with the experimental data and the nuclear equation of state. This can describe the behavior of matter in high density and high pressure in soft EoS, whereas the discrepancy between the results obtained with hard EoS and experimental data that goes up by increasing the centrality transverse component t of the 4-velocity.