SPS和RHIC的多粒子产生  

Analysis of Multi-Particle Production at SPS and RHIC by Two-Source Statistical Model

作　　者：陆中道[1,2] 

机构地区：[1]中国原子能科学研究院,北京102413 [2]中国高等科学技术中心,北京100080

出　　处：《高能物理与核物理》2002年第z1期82-87,共6页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金(19975075)资助

摘　　要：用双源统计模型分别研究了158 A Gev Pb+Pb和(?)s=130 A GeV Au+Au反应中的多粒子产生并与单源统计模型的结果进行了比较.研究表明,前一个反应由内外两个源组成,内源小而热,外源大而较凉;后一个反应有一个高温且大体积的内源.这个源的温度比SPS能量的内源至少高15MeV,体积至少大2倍.文中给出了分析.The data of multi-particle production in 158 A GeV Pb+Pb collisions and (?)s =130 A GeV Au+Au collisions are analyzed by two-source statistical model. It is found that in 158 A GeV Pb+Pb collisions the source is composed of a hot, small inner part and a large, cool outer part. The outer part characterizes the projectile-like and target-like, and the inner part characterizes the central reaction zone. In (?)s =130 A GeV Au+Au collisions, there is a much hotter and larger inner source. The temperature is at least 15MeV higher than that in the inner source in 158 A GeV Pb+Pb collisions. The volume is at least two times of that in the later collision. The reason is that the (?)s =130 A GeV Au+Au collision has large rapidity region [-4.9,4.9], while the experimental data are taken from a small pseudo-rapidity region, |η|<0.5 in which the particles are uniformly distributed as a single source. For a source formed with uniformly-distributed particles, both the single-source statistical model and the two-source statistical model are available, while for a source formed with non-uniformly-distributed particles, only the two-source statistical model is available. The RHIC can provide a hot and large inner source that may be formed in the early stage of hadronization from QGP and may have important physical content behind. We suggest to make synchronous measurement in the outer region, e.g. 3<|y|<4, so as to make comparison.

关 键 词：双源统计模型 SPS能量 RHIC能量 多粒子产生 

分 类 号：O572.21[理学—粒子物理与原子核物理]