Elliptic Flow Splitting between Particles and their Antiparticles in Au+Au Collisions from a Multiphase Transport Model

The elliptic flow v ₂, for ${\pi }^{\pm }$, $K^{\pm }$, p and $\overline{p}$ in Au+Au collisions at center-of-mass energies $\sqrt{s_{NN}}=7.7$, 11.5, 14.5 and 19.6 GeV, is analyzed using a multiphase transport model. A significant difference in the v ₂ values for p and $\overline{p}$ is observed, and the values of v ₂ splitting are larger compared with ${\pi }^{+}$ and ${\pi }^{-}$, $K^{+}$ and $K^{-}$. The difference increases with decreasing the center-of-mass energy. The effect of the quark coalescence mechanism in a multi-phase transport model to the value of elliptic difference $\Delta v_2$ between p and $\overline{p}$ has been discussed. The simulation of Au+Au collisions at 14.5 GeV shows that the effect of hadron cascade to $\Delta v_2$ is not obvious, and a larger parton-scattering cross section can lead to a larger $\Delta v_2$. (paper)