Relativistic Heavy Ion Collision Studies at the LHC and RHIC

众所周知，质子和中子是由称为夸克和胶子的较小成分组成的。在使用两束重原子核的碰撞中，会形成一种新的物质状态，称为夸克-胶子等离子体(QGP)。这个项目将回答有关QGP的基本问题，例如物质如何从质子和中子的集合转变为自由状态，在这种状态下，夸克和胶子可以畅通无阻地在太空中传播，就像他们在大爆炸后的原始物质汤中所做的那样。实验将在位于布鲁克海文国家实验室的相对论重离子对撞机(RHIC)和位于瑞士日内瓦的大型强子对撞机(LHC)进行。为了寻找在给定的光束能量下如何发生到QGP相的转变的信号，俄亥俄州立大学研究小组将研究碰撞中产生的粒子数量以及粒子动量的分布和关联。高能项目的目标有三个。首先，研究在最高能量的重核碰撞中产生的这种密度极高的物质的时空性质。二是研究量子色动力学(QCD)的体相结构，它被认为是夸克与胶子强相互作用的正确理论。这将通过将碰撞的条件改变到较低的能量来实现，以探索受限物质和非受限物质之间的转变(S)。特别是，该小组将进行一项新的分析，作为碰撞能量的函数，测量坐标空间的各向异性和动力学。第三，他们将利用为研究重离子碰撞中的整体物理而开发的工具，并将它们应用于类似能量的质子-质子碰撞。他们将特别关注这些碰撞中的集体行为(流动)。如果高能p+p碰撞中这种流的最初报道在更高的能量下得到证实，这就提出了关于流的性质以及初始自作用状态本身的重要问题。此外，这项提议还在教育、技术和计算机领域对社会产生了更广泛的影响。

It is a well-established fact that protons and neutrons are made up of smaller constituents called quarks and gluons. In collisions using two beams of heavy nuclei, a new state of matter is formed, called the quark-gluon plasma (QGP). This project will answer fundamental questions about the QGP, such as how matter is transformed from a collection of protons and neutrons to a free state where quarks and gluons can travel through space unhindered, much like they did in the primordial soup of matter following the Big Bang. Experiments will be carried out at the Relativistic Heavy Ion Collider (RHIC), located at Brookhaven National Laboratory, and at the Large Hadron Collider (LHC), located in Geneva, Switzerland. In order to look for signatures of how the transition to the QGP phase has occurred for a given beam energy, the Ohio State group will study the numbers of particles produced in the collisions along with the distribution and correlations of particle momenta. The goals for the high-energy program are three-fold. Firstly, to study the space-time properties of this extremely dense matter created in collisions between heavy nuclei at the highest achievable energies. The second is to study the bulk phase structure of Quantum Chromodynamics (QCD), believed to be the correct theory of the Strong interaction between quarks and gluons. 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, the group will perform a novel analysis as a function of the collision energy, measuring coordinate-space anisotropies and dynamics. Thirdly, they will take the tools developed to study bulk physics in heavy ion collisions, and apply them to proton- proton collisions at similar energies. They will look particularly for collective behavior (flow) in these collisions. If the initial reports of such flow in high-energy 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 addition, there are broader impacts to society of this proposal in the areas of education, technology and computing.