A Rigidity Measurement of Pseudo-Rapidity Spectrum of Produced Particles in High Energy Nucleus-Nucleus Collisions

A new concept, rigidity of pseudo-rapidity spectrum, is extended into the study of the multiplicity fluctuations in high energy nucleus-nucleus interactions. In using the novel method to analyze the data of ^l6O-Em at 14.6, 60, and 200A GeV, and ³²S-Em at 200A GeV, it is found that the rigidity of pseudo-rapidity spectrum in the central domain of pseudo-rapidity might be a mixture of Poisson type and Wigner one.