Dynamics of ultradense matter produced in relativistic nuclear collisions

在相对论核碰撞的初始阶段，巨大的能量被沉积在碰撞区域，温度和密度可能高到足以使单个强子失去身份。夸克和胶子现在可以在这个碰撞区域自由运动，而不是被限制在强子中。由此产生的物质被称为夸克-胶子等离子体。强子物质和夸克-胶子等离子体之间的跃迁让我们深入了解了极端条件下夸克和胶子之间的相互作用。它也有助于理解在其他高温和/或高密度区域发生的过程，例如早期宇宙和中子星的核心。为了从实验观测中提取关于夸克-胶子等离子体的信息，为了连接初始的夸克和胶子分布和最终的强子分布，PI将研究在相对论碰撞中产生的强相互作用物质的时空演化的影响。特别是，输运模型方法将被进一步发展并用作主要的理论工具，用于详细研究在自动考虑非平衡和粘性效应的相对论核碰撞中产生的有限大小的超稠密系统的瞬时形成和演化。这项研究将促进对强相互作用物理的理解，这是目前布鲁克海文国家实验室相对论重离子对撞机实验和欧洲核子研究中心未来大型强子对撞机核物理计划的重点。

0140046ZhangDuring the initial stage of relativistic nuclear collisions, enormous amountof energy is deposited in the collision region and the temperature anddensity can be high enough that individual hadrons lose their identities.Instead of being confined in hadrons, quarks and gluons can now move"freely" in this collision region. The matter thus produced is called theQuark-Gluon Plasma. The transition between hadronic matter and theQuark-Gluon Plasma gives us insight into the interactions between quarks andgluons under extreme conditions. It is also useful for the understanding ofprocesses going on in other high temperature and/or high density regions,for example, in the early Universe and in the cores of neutron stars. Toextract information about the Quark-Gluon Plasma from the experimentalobservables, to bridge the initial quark and gluon distributions and thefinal hadron distributions, the PI will investigate the effects of thespace-time evolution of the strongly interacting matter produced inrelativistic collisions. In particular, a transport model approach will befurther developed and used as the major theoretical tool for a detailedstudy of the transient formation and evolution of the finite size,ultradense system produced in relativistic nuclear collisions withnonequilibrium, viscous effects automatically taken into account. Theresearch will advance the understanding of strong interaction physics thatis the focus of current experiments at the Relativistic Heavy Ion Colliderat Brookhaven National Laboratory and the nuclear physics program at thefuture Large Hadron Collider at CERN.