发表机构
Institut für Theoretische Physik, Justus-Liebig-Universität Gießen; Helmholtz Research Academy Hesse for FAIR (HFHF)（吉森大学理论物理研究所; 黑森FAIR亥姆霍兹研究学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究用宇称双重态模型计算核液-气相变附近净重子数涨落，发现其强烈依赖冻结曲线，并成功描述STAR低能数据，表明核子相互作用与液-气相变对涨落有重要贡献。
AI 中文摘要
我们利用平均场近似下的宇称双重态模型（PDM），研究了QCD相图高密度、低温区域中的净重子数涨落。我们计算了核液-气（LG）相变附近直至六阶的涨落比值，其中高阶比值尤为敏感。为了将结果与重离子实验联系起来，我们测试了化学冻结的几种不同情景。我们发现，在LG相变附近，提取的涨落强烈依赖于冻结曲线的选择。我们根据STAR合作组的初步结果自洽地确定了四个冻结点。将实验数据与沿这四个点的PDM结果进行比较，我们发现该模型很好地描述了低能量（$\sqrt{s_{NN}}\lesssim$ 4 GeV）的数据。这表明核子相互作用和LG相变可能对低能量重离子碰撞中的涨落有重要贡献。
英文摘要
We investigate net-baryon number fluctuations in the high-density, low-temperature region of the QCD phase diagram using the parity-doublet model (PDM) under the mean-field approximation. We compute the fluctuation ratios up to sixth order around the nuclear liquid-gas (LG) phase transition, where the high-order ratios are particularly sensitive. To connect the results with heavy-ion experiments, we test several different scenarios of chemical freeze-out. We find that near the LG transition the extracted fluctuations depend strongly on the choice of freeze-out curve. We self-consistently determine four freeze-out points from preliminary results of the STAR Collaboration. Comparing the experimental data with the PDM results along these four points, we find that the model describes the low energy ($\sqrt{s_{NN}}\lesssim$ 4 GeV) data well. This suggests that nucleon interactions and the LG phase transition may contribute significantly to the fluctuations in low energy heavy-ion collisions.
Comments13 pages, 7 figures
