标题： 关于使用EPOS4在重离子碰撞中研究守恒荷二阶累积量的新代理方法的研究 显示英文标题

标题： On the study of new proxies for second order cumulants of conserved charges in heavy-ion collisions with EPOS4

摘要： 对重子数$B$、电荷$Q$和奇异数$S$的累积量的代理通常通过给定强子种类的净数量分布的矩在重离子碰撞中进行测量。 由于这些守恒荷的累积量预计对核物质相图中临界点的存在敏感，因此确保用作替代的代理尽可能接近它们是非常重要的。 因此，我们使用 EPOS4 框架在 RHIC 束能扫描的几个碰撞能量下生成 Au+Au 碰撞。 我们计算$2^\text{nd}$阶的净累积量$\pi$、$K$和$p$，这些已有实验数据发表，以及相应的守恒荷累积量。 然后我们将它们与之前格点 QCD 和强子共振气体模型研究中定义的代理进行比较，这些代理被证明能更准确地再现其相关的守恒荷累积量。 我们研究了系统晚期演化过程中发生的强子再散射对这些量的影响，以及实际来自经历相变的体介质的信号量。 显示英文摘要

摘要： Proxies for cumulants of baryon number $B$, electric charge $Q$ and strangeness $S$ are usually measured in heavy-ion collisions via moments of net-number distribution of given hadronic species. Since these cumulants of conserved charges are expected to be sensitive to the existence of a critical point in the phase diagram of nuclear matter, it is crucial to ensure that the proxies used as substitutes are as close to them as possible. Hence, we use the EPOS4 framework to generate Au+Au collisions at several collision energies of the RHIC Beam Energy Scan. We compute $2^\text{nd}$ order net-cumulants of $\pi$, $K$ and $p$, for which experimental data has been published, as well as the corresponding conserved charge cumulants. We then compare them with proxies, defined in previous lattice QCD and Hadron Resonance Gas model studies, which are shown to reproduce more accurately their associated conserved charge cumulants. We investigate the impact of hadronic re-scatterings occurring in the late evolution of the system on these quantities, as well as the amount of signal actually originating from the bulk medium which endures a phase transition.