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The energy, target-mass, and rapidity-window independence or approximate independence of the multiplicity moments in high-energy nucleus-nucleus collisions are analyzed. It is pointed out that all of these properties are due to nuclear geometry. It is proved under general conditons that, when the target mass is not extremely light and the rapidity window not very narrow, the normalized moments of multiplicity are approximately equal to that of the number of participating nucleons. The calculated results for both minimum-bias and central events agree with recent experimental data.

The rapidity distributions of shower particles in high-energy nucleus-nucleus collisions are investigated and compared with that in hadron-hadron and hadron-nucleus collisions. The remarkable difference in the correlation between rapidity distribution and multiplicity in the three cases, as well as the scaling of rapidity distribution in the target region and the nonscaling of the same distribution in the central region, are explained.