Analysis of Multi-Particle Production at SPS and RHIC by Two-Source Statistical Model
- Received Date: 1900-01-01
- Accepted Date: 1900-01-01
- Available Online: 2002-06-24
Abstract: 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.