The influence of $\pi$N potential on the collective flow of pion mesons in heavy-ion collisions at intermediate energies

Abstract

The pion produced from heavy-ion collisions at intermediate energies is one of the most important probe to investigate the equation of state of dense nuclear matter.However, the pion-nucleon potential which influences the pion propagation through the nuclear medium is not quite clear yet. Within the ultra-relativistic quantum molecular dynamics (UrQMD) model, we introduced a phenomenological pion-nucleon potential and studied its influence on the collective flow of $\pi^{+}$ and $\pi^{-}$ charged mesons. By comparing the model simulations with the corresponding FOPI experimental data, we found that both the rapidity and transverse momentum dependences of the directed and elliptic flows of pion mesons can be semi-quantitatively reproduced by considering a relatively weak pion-nucleon potential, while the calculation results with both a strong pion-nucleon potential and without the pion-nucleon potential are far from the data.