论文标题
流体动力学在重离子碰撞中的适用性在$ \ sqrt {s _ {\ rm nn}} $ = 2.4-7.7 GEV
The applicability of hydrodynamics in heavy ion collisions at $\sqrt{s_{\rm NN}}$= 2.4-7.7 GeV
论文作者
论文摘要
为了评估在低到中间光束能量中重离子反应中产生的物质平衡程度，采用了望子传输方法（SMASH）。通过使用粗粒方法，我们在固定时间步骤中计算系统的能量动量张量，并评估对角线项的各向同性程度和非对角线项的相对大小。这项研究主要集中在能量范围内的AU+AU碰撞上$ \ sqrt {s _ {\ rm nn}} $ = 2.4-7.7 GEV，但也认为较轻离子的中央碰撞也被认为也被认为是。我们发现，在考虑许多事件的平均演变时，在系统的很大一部分时间内，在大部分系统的大部分时间内相当满足了有关局部平衡的条件，但很少会按事件进行事件实现。这与GSI的Hades实验在低光束能量下的杂种方法（或将在RHIC上的Beak Energy扫描程序）上应用。
To assess the degree of equilibration of the matter created in heavy-ion reactions at low to intermediate beam energies, a hadronic transport approach (SMASH) is employed. By using a coarse-graining method, we compute the energy momentum tensor of the system at fixed time steps and evaluate the degree of isotropy of the diagonal terms and the relative magnitude of the off-diagonal terms. This study focuses mostly on Au+Au collisions in the energy range $\sqrt{s_{\rm NN}}$ = 2.4-7.7 GeV, but central collisions of lighter ions like C+C, Ar+KCl and Ag+Ag are considered as well. We find that the conditions concerning local equilibration for a hydrodynamic description are reasonably satisfied in a large portion of the system for a significant amount of time (several fm/c) when considering the average evolution of many events, yet they are rarely fulfilled on an event by event basis. This is relevant for the application of hybrid approaches at low beam energies as they are or will be reached by the HADES experiment at GSI, the future CBM experiment at FAIR as well as the beam energy scan program at RHIC.
