论文标题
LHC能量的PB-PB和P-PB碰撞的流体动力模拟中的散装压力
Bulk pressure in fluid-dynamical simulations of Pb-Pb and p-Pb collisions at the LHC energies
论文作者
论文摘要
对相对论重的重型离子碰撞的最先进的流体动力学模拟采用初始状态模型，从而导致相当强的径向流动。为了拟合实验性可观察物，需要QGP和/或规格的物质的不可忽略的大量粘度。我们研究了在最近流体动力学模拟中使用的块状粘度与熵密度比$ζ/s $的现代参数化，并探讨了时空中相关的散装粘性校正的相对大小，pb-pb和p-pb碰撞在$ \ sqrt {s _ {s _ {\ rm nn} $ 2.76 $ TEV = 2.76 $ TEV = 2.76 $ tev lh HH Trento模型。事实证明，在典型的特色性高表面上，散装粘度的影响超过了剪切粘度之一，而在大量的时空体积中，大量压力强烈抵消平衡压力，因此有效压力接近零。后者有可能挑战重离子离子和质子离子碰撞在LHC能量上的适用性。
State-of-the-art fluid dynamical simulations of relativistic heavy-ion collisions employ initial state models which result in a rather strong radial flow. In order to fit the experimental observables, a non-negligible bulk viscosity of the QGP and/or hadronic matter is required. We examine modern parametrizations of the bulk viscosity to entropy density ratio $ζ/s$ used in recent fluid dynamical simulations, and explore the relative magnitude of the associated bulk viscous corrections in space-time, for Pb-Pb and p-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV LHC energy with a state-of-the-art initial state provided by TRENTo model. It turns out that, at a typical particlization hypersurface, the effect of bulk viscosity out-competes the one of shear viscosity, and in a significantly large part of the space-time volume, the bulk pressure strongly counteracts the equilibrium pressure, thus the effective pressure approaches zero. The latter potentially challenges the applicability of fluid-dynamical modelling of heavy ion-ion and proton-ion collisions at the LHC energies.
