从QCD交叉到核液-气临界性的温度涨落累积量中的相互作用指纹
Interaction fingerprints in temperature-fluctuation cumulants from the QCD crossover to nuclear liquid-gas criticality
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中文总结 AI 辅助
研究相对论重离子碰撞中物质温度涨落累积量，通过计算理想强子共振气体等三种模型中的\(c_2\)、\(c_3\)和\(c_4\)，揭示其在不同条件下表现，将动量涨落与QCD相图热力学结构联系起来。
中文摘要 AI 辅助
相对论重离子碰撞中产生物质的温度涨落与平均横向动量的逐事件涨落相关，并通过比热与QCD状态方程相关。我们计算了理想强子共振气体（HRG）、符合晶格QCD对重子排斥约束的排除体积HRG以及再现核基态的范德瓦尔斯HRG中的温度涨落累积量\(c_2\)、\(c_3\)和\(c_4\)。在零重子密度下，所有三个模型在 chiral crossover之前都与晶格QCD热力学一致，在此之上则分离。沿着化学冻结曲线，对于\(\sqrt{s_{NN}} \gtrsim 20\) GeV，模型保持接近，在较低能量下则强烈分离，此时重子相互作用主导热响应。在范德瓦尔斯模型中，方差\(c_2\)沿着核液-气转变的维德曼线出现最小值，\(c_3\)在其两侧改变符号。因此，温度累积量将平均横向动量涨落与QCD相图两个区域的热力学结构联系起来。
英文摘要
Temperature fluctuations of the matter produced in relativistic heavy-ion collisions are related to event-by-event fluctuations of the mean transverse momentum and, through the specific heat, to the QCD equation of state. We calculate the temperature-fluctuation cumulants $c_2$, $c_3$, and $c_4$ in the ideal hadron resonance gas (HRG), in an excluded-volume HRG consistent with lattice QCD constraints on baryon repulsion, and in a van der Waals HRG that reproduces the nuclear ground state. At zero baryon density all three models agree with lattice QCD thermodynamics up to the chiral crossover and separate above it. Along the chemical freeze-out curve the models remain close for $\sqrt{s_{NN}} \gtrsim 20$ GeV and separate strongly at lower energies, where baryonic interactions dominate the thermal response. In the van der Waals model the variance $c_2$ develops a minimum along the Widom line of the nuclear liquid-gas transition and $c_3$ changes sign across it. Temperature cumulants thus connect mean-transverse-momentum fluctuations to thermodynamic structures in two regions of the QCD phase diagram.
