Relativistic Heavy Ion Collision Studies at the LHC and RHIC

这个奖主要是为了进行相对论性重离子碰撞实验。主要研究人员是俄亥俄州立大学物理系的t·j·哈曼克和m·a·丽莎。我们的高能量项目有三个目标。首先，我们将研究在可达到的最高能量的重核碰撞中产生的极高密度物质的时空特性。认为该物质为夸克-胶子等离子体（QGP），在微观尺度上具有有色自由度。第二个活动是研究量子色动力学（QCD）的体相结构，被认为是正确的部分之间强相互作用的理论。这将通过改变碰撞的条件以降低能量来实现，以探测受限和定义物质之间的转变。特别是，我们计划进行一种新的分析，作为碰撞能量的函数，测量坐标空间各向异性和动力学。第三，我们将把研究重离子碰撞体物理的工具应用到类似能量的强子（p+p）碰撞中。我们将特别关注强子碰撞中的集体行为（流动）。如果我们关于超相对论性p+p碰撞中这种流动的最初报告在更高能量下得到证实，这就提出了关于流动性质和初始自相互作用状态本身性质的重要问题。在目前的资助下，超相对论重离子碰撞将在布鲁克海文国家实验室（BNL）的相对论重离子对撞机（RHIC）和日内瓦欧洲核子研究中心（CERN）的大型强子对撞机（LHC）上进行Au-Au碰撞和Pb-Pb碰撞研究。RHIC在2000年夏天开始进行Au-Au对撞，LHC是目前运行的能量最高的重离子加速器，在2010年底开始进行Pb-Pb对撞。为了寻找已经发生了向夸克物质相变的特征，人们必须研究碰撞中产生的粒子的性质，例如粒子动量和每种类型可以检测到的多样性（例如介子、介子、质子和更多的外来粒子）。这将在RHIC和LHC上完成，分别使用STAR和ALICE实验中可用的大型接受探测器，它们可以对每次碰撞中大多数有趣的粒子进行采样。以这种方式获得的信息可以用来确定，例如，相互作用区域的物理大小（使用双粒子干涉测量法），在碰撞中达到的温度（从粒子动量分布）和奇异粒子的产生，如奇异重子。除了上述智力上的优点外，这一建议在教育、技术和计算领域对社会产生了更广泛的影响。由于本科生、研究生和博士后研究人员将在该项目中发挥关键作用，因此将向这些群体提供如何开展大型合作研究和一般问题解决技能的培训。由于这项研究需要大规模计算来获取和分析teraflop和tb规模的数据，因此将开发计算网格系统等信息科学领域的新方法，从而提高整个社会的计算能力。

This award is primarily to carry out experiments with relativistic heavy ion collisions. The principal investigators are T. J. Humanic and M. A. Lisa, of the Department of Physics at The Ohio State University. Our goals for the high-energy program are threefold. Firstly, we will study the space-time properties of the extremely dense matter created at in collisions between heavy nuclei at the highest achievable energies. It is believed that this matter is a quark-gluon plasma (QGP), characterized by colored degrees of freedom at the microscopic scale. The second activity is to study the bulk phase structure of Quantum Chromodynamics (QCD), believed to be the correct theory of the Strong interaction between partons. This will be achieved by varying the conditions of the collision to lower energies, to probe the transition(s) between confined and deconfined matter. In particular, we plan to perform a novel analysis as a function of the collision energy, measuring coordinate-space anisotropies and dynamics. Thirdly, we will take the tools developed to study bulk physics in heavy ion collisions, and apply them to hadronic(p+p) collisions at similar energies. We will look particularly for collective behaviour(flow) in hadronic collisions. If our initial reports of such flow in ultrarelativistic p+p collisions are confirmed at higher energies, this raises important issues about the nature of flow, and the nature of the initial self-interacting state, itself. In the present grant ultrarelativistic heavy ion collisions will be studied with Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL), and with Pb-Pb collisions at the Large Hadron Collider (LHC) at CERN in Geneva. RHIC started delivering Au-Au collisions in Summer 2000, and the LHC, which is the highest energy heavy ion accelerator now in operation, began delivering Pb-Pb collisions at the end of 2010. In order to look for signatures that a phase transition to Quark Matter has taken place, one must study the properties of the particles produced in the collisions, such as particle momenta and multiplicities of each type that can be detected (e.g. pions, kaons, protons, and more exotic particles). This will be done at both RHIC and the LHC using the large acceptance detectors available in the STAR and ALICE experiments, respectively, which can sample most of the interesting particles per collision. The information obtained in this way can be used to determine, for example, the physical size of the interaction region (using two-particle interferometry), the temperatures reached in the collisions (from particle momentum distributions) and exotic particle production such as strange baryons.Besides the intellectual merit described above, there are broader impacts to society of this proposal in the areas of education, technology and computing. Since undergraduate students, graduate students and postdoctoral researchers will play key roles in this project, training will be provided to these groups in how to carry out research in large collaborations and in general problem solving skills. Since this research requires large-scale computing in order to acquire and analyze data on the teraflop and terabyte scale, new methods in information science, such as computing grid systems, will be developed, which can enhance the computing power of society as a whole.