"Figure 2k" of "Elliptic flow of identified hadrons in Au + Au collisions at s(NN)**(1/2) = 200-GeV."

The anisotropy paramenter ($v_2$), the second harmonic of the azimuthal particles distributions, has been measured with the PHENIX detector in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV for identified and inclusive charged particle production at central rapidities (|$\eta$| = 3-4). We observe that the $v_2$ of mesons falls below that of (anti)baryons for $p_T$ > 2 GeV/$c$, in marked contrast to the predictions of a hydrodynamical model. A quard coalescence model is also investigated.本数据集借助PHENIX探测器，在质心系能量$sqrt{s_{NN}}$=200 GeV的金核-金核（Au+Au）碰撞实验中，针对中心快度区（|$eta$|=3~4）的鉴别粒子与全域带电粒子产生过程，测量了粒子方位角分布的二次谐波——各向异性参数（anisotropy parameter）$v_2$。我们观测到，当横向动量$p_T>2$ GeV/$c$时，介子的$v_2$值低于（反）重子的$v_2$值，这与流体动力学模型的预测结果存在显著差异。本研究同时对夸克合并模型展开了探究。