论文标题
用粘性爆炸波参数化光滑的粘性流体动力学
Parameterizing Smooth Viscous Fluid Dynamics With a Viscous Blast Wave
论文作者
论文摘要
爆炸波拟合被广泛用于高能核碰撞，以捕获动力学平衡附近系统的全球性能的基本特征。它们通常在给定的超表面上提供温度场和集体速度场。我们系统地比较了$ \ sqrt {s_ {nn}} = 200 $ gev和pb+pb碰撞$ \ sqrt {s_ {s_ {nn}} = 2.76 $ tev带有原始模拟的$ \ s_ {nn}} = 200 $ gev和pb+pb碰撞，以$ \ s_ {nn}} = 200 $ gev和pb+pb碰撞进行系统地比较流体动力学模拟的拟合。特别地，我们研究了\ cite {yang：2022yxa}中引入的粘性爆炸波如何在粘性流体动力学计算的冷冻时固定的给定温度和特定的剪切粘度，如果几个粒子的最终光谱和椭圆流。我们发现，粘性爆炸波拟合描述了流体动态伪足相当很好，并将特定的剪切粘度重现至良好的准确性。但是，提取的温度往往被低估了，特别是对于周围碰撞。我们研究了这些偏差的可能原因。我们建立从真实到拟合值的地图。这些地图可用于改善粘性爆炸波拟合的原始拟合结果。尽管我们的工作仅限于两个特定的（尽管很重要的）参数和两个碰撞系统，但可以轻松地将相同的过程推广到其他参数和碰撞系统。
Blast wave fits are widely used in high energy nuclear collisions to capture essential features of global properties of systems near kinetic equilibrium. They usually provide temperature fields and collective velocity fields on a given hypersurface. We systematically compare blast wave fits of fluid dynamic simulations for Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV and Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV with the original simulations. In particular, we investigate how faithful the viscous blast wave introduced in \cite{Yang:2022yxa} can reproduce the given temperature and specific shear viscosity fixed at freeze-out of a viscous fluid dynamic calculation, if the final spectrum and elliptic flow of several particle species are fitted. We find that viscous blast wave fits describe fluid dynamic pseudodata rather well and reproduce the specific shear viscosities to good accuracy. However, extracted temperatures tend to be underpredicted, especially for peripheral collisions. We investigate possible reasons for these deviations. We establish maps from true to fitted values. These maps can be used to improve raw fit results from viscous blast wave fits. Although our work is limited to two specific, albeit important, parameters and two collision systems, the same procedure can be easily generalized to other parameters and collision systems.
