论文标题
通过系统比较Ag+Ag和Au+Au反应在1.23 $ a $ GEV时，探测系统尺寸依赖
Probing system size dependence at high baryon density by systematic comparison of Ag+Ag and Au+Au reactions at 1.23$A$ GeV
论文作者
论文摘要
我们介绍了最近测量的Ag+Ag和Au+Au的比较的URQMD预测，以$ E_ \ MATHRM {lab} $ = 1.23〜 $ a $ GEV探索的光束能量运行。为此，研究了不同的中心性定义：我们建议在粒子产生的情况下，应以相同数量的参与核子进行比较，而为了比较（椭圆形）流动，对初始状态偏心率的选择（如高能量反应）是更好的适合。通常，如果使用这些中心性标准，我们发现两个系统之间的一致性。具体而言，杜特隆的屈服于每个参与者，质子与质子比的比例显示为$ a_ \ mathrm {part} $缩放，除了由于在这种反应中停止更强而导致非常中心的Ag+Ag反应。两个系统中的椭圆流均遵循固态的偏心率缩放，尽管与高能量相比具有相反的符号，这表明最终流与初始状态之间的牢固关系也在此处探索的低能量下。然后，对此缩放的观察可能会允许在高baryon密度下获得有关物质膨胀特性（和EOS）的进一步信息。
We present UrQMD predictions for the comparison of the recently measured Ag+Ag and Au+Au runs at a beam energy of $E_\mathrm{lab}$ = 1.23~$A$GeV explored by the HADES experiment. To this aim, different centrality definitions are investigated: We suggest that in the case of particle production, both systems should be compared at the same number of participating nucleons, while for a comparison of the (elliptic) flow, a selection on the initial state eccentricity - as in high energy reaction - is better suited. Generally, we find good agreement between both system, if these centrality criteria are used. Specifically, the deuteron yields per participant and the pion to proton ratios are shown to scale with $A_\mathrm{part}$ except for very central Ag+Ag reactions due to stronger stopping in such reactions. The elliptic flow in both systems follows inital state eccentricity scaling, albeit with the opposite sign as compared to high energies, suggesting a strong relation between final flows and the initial state also at the low energies explored here. The observation of this scaling might then allow to obtain further information on the expansion properties (and the EoS) of matter at high baryon densities.
