RHIC束流能量扫描实验中正反粒子椭圆流的平均场势效应(英文)
Mean-field Effects on Particle and Antiparticle Elliptic Flows in the Beam-energy Scan Program at RHIC
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摘要: 最近,STAR合作体在相对论重离子对撞机的束流能量扫描实验中观测到了正反粒子的椭圆流劈裂。基于输运模型,发现丰重子介质中正反粒子平均场势的不同可以解释其椭圆流的劈裂。利用Nambu-Jona-Lasinio 模型描述相对论重离子碰撞的部分子相,发现实验中正反粒子的相对椭圆流劈裂可以用来约束该模型中夸克矢量相互作用的耦合系数。这一发现对确定QCD相图的临界点位置和理解整个QCD的相结构有重要意义。The elliptic flow splitting between particles and their antiparticles has recently been observed by the STAR Collaboration in the beam-energy scan program at the Relativistic Heavy Ion Collider. In studies based on transport models, we have found that this splitting can be explained by the different mean-field potentials acting on particles and their antiparticles in the produced baryon-rich matter. In particular, we have shown that the experimentally measured relative elliptic flow difference can help constrain the vector coupling constant in the Nambu-Jona-Lasinio model used in describing the partonic stage of heavy-ion collisions. This information is useful for locating the critical point in the QCD phase diagram and thus understanding the phase structure of QCD.Abstract: The elliptic flow splitting between particles and their antiparticles has recently been observed by the STAR Collaboration in the beam-energy scan program at the Relativistic Heavy Ion Collider. In studies based on transport models, we have found that this splitting can be explained by the different mean-field potentials acting on particles and their antiparticles in the produced baryon-rich matter. In particular, we have shown that the experimentally measured relative elliptic flow difference can help constrain the vector coupling constant in the Nambu-Jona-Lasinio model used in describing the partonic stage of heavy-ion collisions. This information is useful for locating the critical point in the QCD phase diagram and thus understanding the phase structure of QCD.