Analysis of multi-particle production at RHIC by two-source statistical model

The data of multi-particle production in root SNN = 130 GeV Au + Au collisions are analyzed by two-source statistical model. It is found that in this reaction the two sources (inner source and outer source) are identical. They have the same temperature, volume, particle density and other thermodynamic quantities. Besides, the results of two-source model are identical with that of single-source model (the total volume of the two sources equals the volume of single source). The identities between two sources and between two models are due to the particles being measured in a limited central rapidity region. The root SNN = 130 GeV Au + Au collision has large rapidity region [-4.9, 4.9], while data are taken from a small pseudo-rapidity region, |η| lt; 0.5. In the region, the particles are uniformly distributed as a single source. Comparing to the inner source in 158 A GeV/c Pb + Pb collision, which has a small and hot inner source surrounded by a larger and cooler outer source, the temperature is at least 15MeV higher and the volume is at least two times larger. 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 less than or equal |y| less than or equal 4, so as to make comparison.