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arXiv 2403.02306hep-phnucl-th
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利用 EPOS4 研究重离子碰撞中守恒电荷二阶累积量的新型代理量

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

Johannes Jahan, Claudia Ratti, Maria Stefaniak, Klaus Werner

AI总结:

该研究利用 EPOS4 模拟 RHIC 束能扫描中的 Au+Au 碰撞,比较强子净数二阶累积量、守恒电荷累积量及新型代理量,并考察强子再散射和相变介质信号的影响。

摘要:

在重离子碰撞中,重子数 $B$、电荷 $Q$ 和奇异数 $S$ 的累积量代理量通常通过给定强子种类净数分布的矩来测量。由于这些守恒电荷累积量被认为对核物质相图中临界点的存在十分敏感,因此确保用作替代的代理量尽可能接近它们至关重要。为此,我们使用 EPOS4 框架,在 RHIC 束流能量扫描的若干碰撞能量下生成 Au+Au 碰撞。我们计算了已有实验数据发表的 $π$、$K$ 和 $p$ 的二阶净累积量,以及相应的守恒电荷累积量。随后,我们将其与此前 lattice QCD(格点 QCD)和 Hadron Resonance Gas(强子共振气)模型研究中定义的代理量进行比较;这些代理量被证明能够更准确地再现与其相关的守恒电荷累积量。我们研究了系统晚期演化中发生的强子再散射对这些量的影响,以及真正源自经历相变的整体介质的信号所占比例。

英文摘要:

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 $π$, $K$ 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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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