Azimuthal emission patterns of proton in ⁵⁸Ni + ⁵⁸Ni collision at intermediate energy by using a quantum molecular dynamics model

The direct flow of a proton in the ⁵⁸Ni + ⁵⁸Ni collisions at incident energy 1.93 A GeV was computed by using a quantum molecular dynamics model (QMD). The mean transverse momentum projected on the reaction plane as a function normalized rapidity for the proton (〈p_x/m_p〉 (Y⁽⁰⁾)) from ⁵⁸Ni + ⁵⁸Ni collisions with impact parameter (b) < 4 fm was studied. Furthermore, the direct flow of the proton as a function of th transverse momentum (v ₁(p_t)) at the incident energy 1.93 A GeV with b < 2.5 fm was investigated by taking into account the nuclear equation of state (hard and soft EoS). The theoretical results were compared with KaoS experiment and BUU model. The calculated results show that the theoretical calculations of the 〈p_x/m_p〉 (Y⁰), a soft EoS is consistent with experimental data. In addition, the v ₁(p_t) is confirmed by the soft EoS that is good agreement with the experimental data at the p_t < 0.6. Consequently, this work indicates that 〈p_x/m_p〉 (Y⁽⁰⁾) and v ₁(p_t) are sensitive observable to probe the nuclear equation of state in dense nuclear matter. (paper)