Complementary two-particle correlation observables for relativistic nuclear collisions
Complementary two-particle correlation observables for relativistic nuclear collisions
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DOI：
10.1103/physrevc.107.014909
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发表时间：
2021-10
影响因子：
3.1
通讯作者：
M. Cody;S. Gavin;B. Koch;Mark Kocherovsky;Zoulfekar Mazloum;G. Moschelli
中科院分区：
文献类型：
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作者：
M. Cody;S. Gavin;B. Koch;Mark Kocherovsky;Zoulfekar Mazloum;G. Moschelli
两粒子关联是研究相对论性核碰撞的一个广泛使用的工具。研究了电荷和粒子种类的多重数涨落作为夸克胶子等离子体（QGP）和QCD临界点的可能信号。这些涨落研究都利用了粒子方差，这可以被证明是源于两粒子相关函数。动量关联和协方差的动量涨落，这引起了相同的相关函数，也被用来提取核碰撞介质的性质，如剪切粘度熵密度比，剪切松弛时间，和温度涨落。临界涨落的检验也是用这些相关观测量来完成的。我们推导出几个数和动量密度相关观测值之间的数学关系，并概述了不同的物理机制往往归因于每一个。这组观测值还包含一个新的多重性动量相关。我们的数学关系可以用作测量的验证工具，作为解释不同物理机制对相关观测量的相对贡献的方法，以及作为同时解释所有观测量的理论和唯象模型的测试。我们比较了一个独立的源模型，模拟事件PYTHIA的所有观测值的集合。
Two-particle correlations are a widely used tool for studying relativistic nuclear collisions. Multiplicity fluctuations comparing charge and particle species have been studied as a possible signal for Quark-Gluon Plasma (QGP) and the QCD critical point. These fluctuation studies all make use of particle variances which can be shown to originate with a two-particle correlation function. Momentum correlations and covariances of momentum fluctuations, which arise from the same correlation function, have also been used to extract properties of the nuclear collision medium such as the shear viscosity to entropy density ratio, the shear relaxation time, and temperature fluctuations. Searches for critical fluctuations are also done with these correlation observables. We derive a mathematical relationship between several number and momentum density correlation observables and outline the different physics mechanisms often ascribed to each. This set of observables also contains a new multiplicity-momentum correlation. Our mathematical relation can be used as a validation tool for measurements, as a method for interpreting the relative contributions of different physics mechanisms on correlation observables, and as a test for theoretical and phenomenological models to simultaneously explain all observables. We compare an independent source model to simulated events from PYTHIA for all observables in the set.