发表机构
Frankfurt Institute for Advanced Studies; Institute for Theoretical Physics, Goethe University; GSI Helmholtzzentrum für Schwerionenforschung; Helmholtz Research Academy Hesse for FAIR (HFHF)（法兰克福高级研究所; 歌德大学理论物理研究所; GSI亥姆霍兹重离子研究中心; 黑森FAIR亥姆霍兹研究院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过SMASH、SMASH+Ropes和SMASH+vHLLE模型比较，发现奇异粒子增强不能单独区分色绳与流体动力学机制，需结合横向动力学来辨别热与非热过程。
AI 中文摘要
我们使用输运方法SMASH（模拟大量加速强相互作用强子）及其带有绳强子化的扩展，以及SMASH+vHLLE混合方法，研究了在$\/sqrt{s_{\mathrm{NN}}}\approx 2.5-20~\mathrm{GeV}$的重离子碰撞中的奇异粒子产生和横向动力学。为了比较，还包含了基于Pythia的重离子模型Angantyr的结果，该模型有和没有绳强子化。我们研究了作为受伤核子数函数的中心快度粒子产额和平均横向质量，以及它们的能量依赖性。对于$K^+/\pi^+$比率，SMASH+vHLLE在低能量下过度预测了奇异粒子产生，但在较高能量下描述得相当好。SMASH+Ropes在$\sqrt{s_{\mathrm{NN}}}\sim 10~\mathrm{GeV}$之前重现了该比率，但未能捕捉到更高能量下的转折。相反，横向质量观测量更倾向于混合方法，而这里考虑的非热模型没有产生足够的集体横向膨胀。这些结果表明，仅奇异粒子增强并不能唯一区分微观弦相互作用与局部平衡介质。因此，同时约束奇异粒子产生和横向动力学对于解开重离子碰撞中的热和非热机制至关重要。
英文摘要
We investigate strangeness production and transverse dynamics in heavy-ion collisions at $\sqrt{s_{\mathrm{NN}}}\approx 2.5-20~\mathrm{GeV}$ using the transport approach SMASH (Simulating Many Accelerated Strongly-interacting Hadrons), its extension with rope hadronization, and the SMASH+vHLLE hybrid approach. Results from the Pythia-based heavy-ion model Angantyr, with and without rope hadronization, are included for comparison. We study midrapidity particle yields and average transverse masses as functions of the number of wounded nucleons, as well as their energy dependence. For the $K^+/π^+$ ratio, SMASH+vHLLE overpredicts strangeness production at low energies but describes the higher-energy behavior reasonably well. SMASH+Ropes reproduces the ratio up to $\sqrt{s_{\mathrm{NN}}}\sim 10~\mathrm{GeV}$ but does not capture the turnover at higher energies. In contrast, the transverse-mass observables favor the hybrid approach, while the non-thermal models considered here do not generate sufficient collective transverse expansion. These results show that strangeness enhancement alone does not uniquely distinguish microscopic string interactions from a locally equilibrated medium. Simultaneously constraining strangeness production and transverse dynamics is therefore essential for disentangling thermal and non-thermal mechanisms in heavy-ion collisions.
