论文标题
$ \ sqrt {s _ {\ rm nn}} = 5.02 $ tev for pp，p-pb和pb-pb碰撞的系统尺寸依赖性$ \ sqrt {s _ {\ rm nn}} = 5.02 $ tev
System-size dependence of the charged-particle pseudorapidity density at $\sqrt{s_{\rm NN}} = 5.02$ TeV for pp, p-Pb, and Pb-Pb collisions
论文作者
论文摘要
我们介绍了三种截然不同的碰撞系统，PP，P-PB和PB-PB的第一个系统比较，位于大型强子对撞机的最高能量（$ \ sqrt {s _ {\ rm nn}}} = 5.02 $ tev）上，该范围超过了Pseudorapidity（$ \ rm nn}} = 5.02 $ tev） <η<5} $），这是该设施的四个实验中最大的。由于测量值是通过相同的实验设备（Alice）记录的，因此系统的不确定性被最小化。 P-PB和PB-PB碰撞的分布是根据碰撞中心性的函数确定的，而PP碰撞的结果是在中间差异至少有一个带电粒子的无弹性事件的结果。在简单且稳健的假设下，带电的颗粒假性密度转化为带电的粒子速度密度。这允许计算和表示快速分布的宽度的演变和Bjorken能量密度的下限，这是所有三个碰撞系统中参与者数量的函数。我们发现粒子产生的宽度下降，随着系统尺寸的增长，能量密度大约增加了十倍，这与逐渐更高的物质相位一致。
We present the first systematic comparison of the charged-particle pseudorapidity densities for three widely different collision systems, pp, p-Pb, and Pb-Pb, at the top energy of the Large Hadron Collider ($\sqrt{s_{\rm NN}} = 5.02$ TeV) measured over a wide pseudorapidity range (${-3.5 <η<5}$), the widest possible among the four experiments at that facility. The systematic uncertainties are minimised since the measurements are recorded by the same experimental apparatus (ALICE). The distributions for p-Pb and Pb-Pb collisions are determined as a function of the centrality of the collisions, while results from pp collisions are reported for inelastic events with at least one charged particle at midrapidity. The charged-particle pseudorapidity densities are, under simple and robust assumptions, transformed to charged-particle rapidity densities. This allows for the calculation and the presentation of the evolution of the width of the rapidity distributions and of a lower bound on the Bjorken energy density, as a function of the number of participants in all three collision systems. We find a decreasing width of the particle production, and roughly a smooth ten fold increase in the energy density, as the system size grows, which is consistent with a gradually higher dense phase of matter.
