Scaling of v2 in heavy ion collisions
Scaling of v2 in heavy ion collisions
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DOI：
10.1103/physrevc.76.024903
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发表时间：
2007-02
影响因子：
3.1
通讯作者：
G. Torrieri
中科院分区：
文献类型：
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作者：
G. Torrieri
我们解释了校正椭圆流参数相对于校正多重性的缩放，观察到在各种能量和系统尺寸的重离子碰撞中保持不变。我们使用量纲分析和功率计算论证来对具有不同质心能量√s的系统的初始条件的变化施加约束。具体来说，我们表明，（初始）状态方程、平均自由程和观察到的 √s 上的纵向几何的一大类变化可能会破坏实验观察到的 v 2 的缩放。因此，我们认为，就软自由度和近似热化自由度而言，在大多数超级质子同步加速器（SPS）和相对论重离子对撞机（RHIC）能量下产生的系统基本上是相同的。因此，“sQGP”（强相互作用夸克-胶子等离子体）相（如果存在）并非 RHIC 所独有。我们建议，作为进一步低能重离子实验的目标，寻找观察到的尺度断裂的“转变”√s。
We interpret the scaling of the corrected elliptic flow parameter with respect to the corrected multiplicity, observed to hold in heavy ion collisions for a wide variety of energies and system sizes. We use dimensional analysis and power-counting arguments to place constraints on the changes of initial conditions in systems with different center of mass energy √s. Specifically, we show that a large class of changes in the (initial) equation of state, mean free path, and longitudinal geometry over the observed √s are likely to spoil the scaling in v 2 observed experimentally. We therefore argue that the system produced at most Super Proton Synchrotron (SPS) and Relativistic Heavy Ion Collider (RHIC) energies is fundamentally the same as far as the soft and approximately thermalized degrees of freedom are considered. The "sQGP" (Strongly interacting Quark-Gluon Plasma) phase, if it is there, is therefore not exclusive to RHIC. We suggest, as a goal for further low-energy heavy ion experiments, to search for a "transition" √s where the observed scaling breaks.