论文标题
高能核碰撞中方位角相关的多粒子累积物的通用算法
Generic algorithm for multi-particle cumulants of azimuthal correlations in high energy nucleus collisions
论文作者
论文摘要
方位角相关性的多粒子累积物已引人注目的工具，可以探测在超占领的重型离子碰撞中创建的夸克 - 胶状等离子体（QGP），并在RHIC和LHC中搜索小型碰撞系统中的QGP。但是，其中只有很少的可用，并且已经在理论计算和实验测量中进行了研究。在本文中，我们提出了用于多粒子累积物的通用递归算法，该算法可以计算任意阶多粒子累积物。其中，单个谐波的新的10-，12-，14-和16个粒子累积物为$ c_ {n} \ {10 \} $，$ c_ {n} \ {12 \} $，$ c_ {n}系数将首次讨论。这些新的多粒子累积物可以很容易地使用，并更新到非常高阶的多粒子相关性的通用框架。最后，我们提出了一系列特定的混合谐波多粒子累积物，该累积物测量了不同流量系数的任何矩之间的一般相关性。这些新可观察物的预测是根据初始状态模型MC-Glauber（玩具蒙特卡洛模型）以及用于实验数据和理论模型计算之间将来比较的Hijing Transper模型所显示的。对重离子碰撞中这些新的多粒子累积物的研究将显着提高对关节概率密度函数的理解，该概率函数既涉及流动的不同谐波，又涉及对称平面。这将为对初始状态的更严格的约束铺平道路，并有助于更准确地提取创建的热和密集物质的发展方式。同时，适用于小型系统的努力可能对理解RHIC和LHC观察到的集体的起源非常有帮助。
Multi-particle cumulants of azimuthal angle correlations have been compelling tools to probe the properties of the Quark-Gluon Plasma (QGP) created in the ultra-relativistic heavy-ion collisions and the search for the QGP in small collision systems at RHIC and the LHC. However, only very few of them are available and have been studied in theoretical calculations and experimental measurements. In this paper, we present a generic recursive algorithm for multi-particle cumulants, which enables the calculation of arbitrary order multi-particle cumulants. Among them, the new 10-, 12-, 14-, and 16-particle cumulants of a single harmonic, named $c_{n}\{10\}$, $c_{n}\{12\}$, $c_{n}\{14\}$, and $c_{n}\{16\}$, and the corresponding $v_n$ coefficients, will be discussed for the first time. These new multi-particle cumulants can be readily used along with updates to the generic framework of multi-particle correlations to a very high order. Finally, we propose a particular series of mixed harmonic multi-particle cumulants, which measures the general correlations between any moments of different flow coefficients. The predictions of these new observables are shown based on an initial state model MC-Glauber, a toy Monte Carlo model, and the HIJING transport model for future comparisons between experimental data and theoretical model calculations. The study of these new multi-particle cumulants in heavy-ion collisions will significantly improve the understanding of the joint probability density function which involves both different harmonics of flow and also the symmetry planes. This will pave the way for more stringent constraints on the initial state and help to extract more precisely how the created hot and dense matter evolves. Meanwhile, the efforts applied to small systems could be very helpful in the understanding of the origin of the observed collectivity at RHIC and the LHC.
