Abstract

Determining the centrality of a collision, or the impact parameter, in heavy-nucleus collisions is important for the analysis of all experimental data and their comparison with theory. One of the methods for this is to measure the number of spectators using a hadron calorimeter arranged at a small angle to the nuclear beam. It is shown that the accuracy in determining the impact parameter at the attainable energy resolution of the hadron calorimeter is inadequate for using the calorimeter in the MPD/NICA and CBM/FAIR projects. The error is as large as 35% at the beam energy of 2.5 GeV even for peripheral collisions. Secondary processes during the motion of spectators through a nucleus make an additional contribution to the error for central and mid-central collisions.

中文翻译：

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使用强子量热仪确定核碰撞的中心性

摘要

确定重核碰撞中的碰撞中心性或碰撞参数对于分析所有实验数据并将其与理论进行比较非常重要。一种方法是使用与核束成小角度布置的强子量热仪来测量观众的数量。结果表明，在强子量热仪的可达到的能量分辨率下确定冲击参数的准确性不足以在MPD / NICA和CBM / FAIR项目中使用量热仪。即使对于周围碰撞，在2.5 GeV的光束能量下，误差也高达35％。旁观者通过核运动过程中的次要过程为中央和中部碰撞的误差做出了额外贡献。