Production of negatives and protons in nucleus-nucleus collisions at AGS and SPS energies

We study systematically the negative and proton rapidity distributions in nucleus-nucleus collisions at the AGS and SPS energies within the thermalized cylinder model and the three-fireball model. The calculated results are compared with the available experimental data. It is shown that the calculated negative rapidity distributions by the two models are very similar, if not equal. The structure of rapidity distribution for protons is more complex than that for negatives. The thermalized cylinder model is better than the three-fireball model in description of proton rapidity distribution. The thermalized cylinder model is successful at the AGS and SPS energies. The three-fireball model is successful at the AGS energy and partly successful at the SPS energy. (Author)