Disentangling contributions to small-system collectivity via scans of light nucleus-nucleus collisions
Disentangling contributions to small-system collectivity via scans of light nucleus-nucleus collisions
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DOI：
10.1103/physrevc.101.021901
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发表时间：
2019-04
影响因子：
3.1
通讯作者：
S. Huang;Zhenyu Chen;Wei Li-;J. Jia
中科院分区：
文献类型：
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作者：
S. Huang;Zhenyu Chen;Wei Li-;J. Jia
高能小系统碰撞中多粒子方位角关联的观测导致了关于其起源和可能共存的两种相互竞争的理论方案的激烈争论：一种基于初始态内禀动量各向异性，另一种基于最终态相互作用模型（FSM）对碰撞几何的集体响应。为了补充先前对非对称碰撞系统（p+Au，d+Au和He+Au）的扫描，我们提出了在布鲁克海文国家实验室相对论重离子对撞机上对小型对称碰撞系统（如C+C，O+O，Al+Al和Ar+ArsNN=0.2TeV）进行扫描，以进一步了解这两种情况的贡献。这些对称的小系统具有提供由重叠区域的平均形状主导的更好的受控初始几何形状的优点，这与不对称系统中的波动驱动的几何形状相反。一个传输模型，调查FSM方案中的预期几何响应。不同的趋势，椭圆形流动与增加的电荷粒子的多重性之间观察到对称和非对称系统，而三角形流似乎表现出类似的行为。此外，欧洲核子研究中心大型强子对撞机（CERN Large Hadron Collider）提出的sNN=0.2TeV和sNN=2.76−7TeV的O+O碰撞的比较，提供了一个独特的机会，可以将核子水平的碰撞几何效应与亚核子涨落的碰撞几何效应分开。
The observation of multiparticle azimuthal correlations in high-energy small-system collisions has led to intense debate on its origin and the possible coexistence from two competing theoretical scenarios: one based on initial-state intrinsic momentum anisotropy, and the other based on final-state interaction model (FSM) collective response to the collision geometry. To complement the previous scan of asymmetric collision systems (p+Au,d+Au, and He+Au), we propose a scan of small symmetric collision systems at the Brookhaven National Laboratory Relativistic Heavy Ion Collider, such as C+C, O+O, Al+Al, and Ar+ArsNN=0.2TeV, to provide further insights in disentangling contributions from these two scenarios. These symmetric small systems have the advantage of providing a better controlled initial geometry dominated by the average shape of the overlap region as opposed to fluctuation-driven geometries in asymmetric systems. A transport model is employed to investigate the expected geometry response in the FSM scenario. Different trends of elliptic flow with increasing charge particle multiplicity are observed between symmetric and asymmetric systems, whereas triangular flow appears to show a similar behavior. Furthermore, a comparison of O+O collisions at sNN=0.2TeV and at sNN=2.76−7TeV as proposed at the CERN Large Hadron Collider, provides a unique opportunity to disentangle the collision geometry effects at the nucleon level from those arising from subnucleon fluctuations.