Multisystem Bayesian constraints on the transport coefficients of QCD matter
Multisystem Bayesian constraints on the transport coefficients of QCD matter
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DOI：
10.1103/physrevc.103.054904
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
D. Everett;W. Ke;J. Paquet;G. Vujanovic;S. Bass;L. Du;C. Gale;M. Heffernan;U. Heinz;
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文献类型：
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作者：
D. Everett;W. Ke;J. Paquet;G. Vujanovic;S. Bass;L. Du;C. Gale;M. Heffernan;U. Heinz;
我们研究了强耦合的夸克胶子等离子体的性质与重离子碰撞的多级模型，结合了T$\mathrm{R}$ENTo初始条件的无规性，自由流，粘性相对论流体力学，和相对论强子输运。与贝叶斯推理的模型到数据的比较，重新审视在以前的研究中所作的假设。参数先验的作用进行了研究，在他们的重要性对结果的解释。我们强调使用封闭测试来进行广泛的验证分析工作流程之前，与观察。我们的研究结合了大型强子对撞机和相对论重离子对撞机的测量，实现了很好的同时描述了两个对撞机的广泛的强子观测。所选的实验数据提供合理的约束的剪切和体的夸克胶子等离子体的粘度在$T\sim $150 -250 MeV，但其约束力在更高的温度下下降$T \gtrsim 250$ MeV。此外，这些粘性约束被发现显着依赖于如何粘性修正处理的过渡，从流体力学的强子输运。其他几个模型参数，包括自由流动时间，表现出类似的模型灵敏度，而与T$\mathrm{R}$ENTo的初始条件参数是相当强大的粒子化处方的变化。我们还报告的敏感性，个别观测到的各种模型参数。最后，贝叶斯模型的选择是用来定量比较协议与测量不同的模型假设，包括不同的粒子化模型和不同的选择，参数允许RHIC和LHC能量之间的变化。
We study the properties of the strongly-coupled quark-gluon plasma with a multistage model of heavy ion collisions that combines the T$_\mathrm{R}$ENTo initial condition ansatz, free-streaming, viscous relativistic hydrodynamics, and a relativistic hadronic transport. A model-to-data comparison with Bayesian inference is performed, revisiting assumptions made in previous studies. The role of parameter priors is studied in light of their importance towards the interpretation of results. We emphasize the use of closure tests to perform extensive validation of the analysis workflow before comparison with observations. Our study combines measurements from the Large Hadron Collider and the Relativistic Heavy Ion Collider, achieving a good simultaneous description of a wide range of hadronic observables from both colliders. The selected experimental data provide reasonable constraints on the shear and the bulk viscosities of the quark-gluon plasma at $T\sim$ 150-250 MeV, but their constraining power degrades at higher temperatures $T \gtrsim 250$ MeV. Furthermore, these viscosity constraints are found to depend significantly on how viscous corrections are handled in the transition from hydrodynamics to the hadronic transport. Several other model parameters, including the free-streaming time, show similar model sensitivity while the initial condition parameters associated with the T$_\mathrm{R}$ENTo ansatz are quite robust against variations of the particlization prescription. We also report on the sensitivity of individual observables to the various model parameters. Finally, Bayesian model selection is used to quantitatively compare the agreement with measurements for different sets of model assumptions, including different particlization models and different choices for which parameters are allowed to vary between RHIC and LHC energies.