Effects of mean-field and the softening of equation of state on elliptic flow in Au+Au collision at $\sqrt{s_{NN}}$ = 5 GeV from JAM model

TL;DR

This study uses the JAM transport model to analyze how mean-field effects and EoS softening influence elliptic flow in Au+Au collisions at 5 GeV, revealing sensitivity to phase transition signatures.

Contribution

It demonstrates how EoS softening and mean-field effects distinctly impact elliptic flow, providing insights into the QCD phase transition at high baryon densities.

Findings

EoS softening enhances elliptic flow $v_2$.

Hadronic mean-field suppresses $v_2$.

Elliptic flow is sensitive to the equation of state at high baryon density.

Abstract

We perform a systematic study of elliptic flow ($v_2$) in Au+Au collision at $\sqrt{s_{NN}}=5$ GeV by using a microscopic transport model JAM. The centrality, pseudorapidity, transverse momentum and beam energy dependence of $v_2$ for charged as well as identified hadrons are studied. We investigate the effects of both the hadronic mean-field and the softening of equation of state (EoS) on elliptic flow. The softening of EoS is realized by imposing attractive orbits in two body scattering, which can reduce the pressure of the system. We found that the softening of EoS leads to the enhancement of $v_2$, while the hadronic mean-field suppresses $v_2$ relative to the cascade mode. It indicates that elliptic flow at high baryon density regions is highly sensitive to the EoS and the enhancement of $v_2$ may probe the signature of a first-order phase transition in heavy-ion collisions at beam energies of a strong baryon stopping region.