Studies of Relativisitic Heavy Ion Collision at CERN and RHIC

该项目的主要物理目标有两个：1）在实验室中通过加热/压缩正常核物质到足够高的温度/密度来创造一种称为“夸克物质”的新物质状态，同样重要的是，2）唯一地确定这种向夸克物质的转变是否真的发生了。夸克物质由“自由”夸克和胶子组成，这些基本粒子被束缚成质子和中子，构成正常的核物质。据预测，宇宙在大爆炸后百万分之几秒完全处于夸克物质状态。我们将用来制造夸克物质的方法将是碰撞以接近光速移动的重核束（例如铅对铅和金对金）。这些光束将由位于长岛布鲁克海文国家实验室和日内瓦欧洲核子研究中心实验室的最先进的粒子加速器产生。为了确定夸克物质是否真的在这些高能重离子碰撞中产生，将出现大粒子探测器来探测产生的次级粒子（主要是π和K介子以及一系列更奇特的粒子）。理论预测，夸克物质形成的独特特征可以从这些次级粒子获得的信息中提取出来。俄亥俄州州立大学小组的作用是参与开发一种用于这些二次粒子的新型粒子探测器，称为“硅漂移探测器”，并分析我们在这些实验中收集的数据，希望提取独特的夸克物质特征。

The main physics goals of this project are two-fold: 1) to create in the laboratory a new state of matter called "Quark Matter" by heating/ compressing normal nuclear matter to a sufficiently high temperature/ density, and, equally important, 2) to uniquely determine whether such a transformation to Quark Matter has actually taken place. Quark Matter is composed of "free" quarks and gluons, the fundamental particles which are bound into protons and neutrons which make up normal nuclear matter. It is predicted that the Universe was entirely in the Quark Matter state several millionths of a second after the Big Bang. The method which we will use to make Quark Matter will be to collide beams of heavy nuclei (e.g. lead on lead and gold on gold) moving at speeds near the speed of light. These beams will be generated by new state-of-the-art particle accelerators located at Brookhaven National Laboratory on Long Island and at the CERN laboratory in Geneva. To determine whether Quark Matter has actually been created in these high energy heavy ion collisions, large particle detectors will be present to detect the secondary particles which are produced (mostly pi and K mesons and a range of more exotic particles). Theories predict that unique signatures for Quark Matter formation can be extracted from information obtained from these secondary particles. The role of the Ohio State University group is to participate in developing a new type of particle detector for these secondary particles called a "Silicon Drift Detector" and to analyze the data which we collect in these experiments to, hopefully, extract unique Quark Matter signatures.