Experimental Study on Quark-Gluon-Plasma at BNL

BNL 夸克-胶子-等离子体实验研究

基本信息

批准号：
03044034
负责人：
HOMMA Saburo
金额：
$ 5.76万
依托单位：
Institute for Nuclear Study, University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

The experiment with high-intensity 14.5 AGeV Si-beams and the first-round experiment with 11 AGeV Au-beams have been carried out by the Japan-US international collaboration in high energy heavy ion collisions at the AGS, Brookhaven National Laboratory, USA.Primary goals of the experiment are (1) to study the two-particle correlations for pions and Kaons, and (2) to measure the rarely-produced hadrons (i.e. K-and anti-proton) with good statistics using the experimental system with a magnetic spectrometer as a central device.Space-time evolution of nucleus-nucleus collisions could be investigated through two-particle correlation measurement. Trial of measuring K-and anti-proton were made before, but low statistics prevented us to deduce any conclusions for their productions.In order to achieve the goals, we built a special trigger system by which particle identification in the trigger-level was made possible. Stringent event selection capability made it possible to run with high-intensity beams.Data analyses of two particle correlations are in progress, and preliminary result shows that source size measuremed by pions is significantly smaller than that measured by Kaons.Anti-proton yield was consisten with the model calculation with no anti-protons absorption in nuclear matter, which strongly contradicts to the naive expectation.With the completion of AGS-Booster, experiments with heavy ions up to Au became possible. We can expect a better condition to study unclear matter at extreme conditions with heavy ions. The first Au beam was available in May, 1992, and we had a prelminary short run. Purity of Au beam was better than 99%. Measurements of transverse and forward energy flow were made. Measurement of particle spectra at backward angle with spectrometer were also tried.Data analysis going on, and the construction of a new spectrometer which covers the forward angular region is in progress.

高强度14.5 Agev SI梁和首轮实验的实验是由日本美国美国国际高能重离子碰撞的国际合作进行的，美国布鲁克黑文国家实验室的高能量重离子碰撞。（即K-and Anti-Proton）使用具有磁性光谱仪作为中央装置的实验系统具有良好的统计数据。可以通过两粒子相关测量来研究Nucleus-Nucleus碰撞的空间演化。以前进行了测量K和反普罗顿的试验，但低统计数据阻止我们推断出其生产的任何结论。为了实现目标，我们建立了一个特殊的触发系统，通过该系统，通过该系统使触发器级别的粒子识别成为可能。严格的事件选择能力使得有两个粒子相关的数据分析正在进行中。具有重型离子直至AU的实验变得可能是可能的。我们可以期望有更好的条件在具有重离子的极端条件下研究不清楚的物质。 1992年5月，第一个AU梁可用，我们进行了初步短期。 AU梁的纯度大于99％。进行了横向和正向能流的测量。还尝试了以光谱仪向后角度测量粒子光谱。数据进行分析，并且正在进行覆盖向前角区域的新光谱仪的构建正在进行中。