论文标题
净 - 蛋白质数累积比作为梁能量的函数，来自膨胀的非平衡性手流体
Net-proton number cumulant ratios as function of beam energy from an expanding nonequilibrium chiral fluid
论文作者
论文摘要
RHIC的Beam Energy扫描程序提供了有关Net-Proton数量波动的数据，其目标是检测QCD临界终点和一阶相变。解释这些实验信号需要对临界现象的相互作用和快速扩展的火球的非平衡动力学有重要的了解。我们以流体动力膨胀来研究这些方面，并通过langevin方程进行了手性阶参数sigma的显式传播。假设通过有效的质子质量进行Sigma-Proton耦合，我们将阶参数的累积物与冻结时的净蛋白量相关联，并获得可观察到的累积比与梁能量的函数。我们强调了非平衡一阶相变的作用，即具有逐渐冻结的混合相可以显着改变累积剂。我们发现，对于相对较大的质量中心能量，累积比率清楚地看到了临界终点的存在。
The beam energy scan program at RHIC provides data on net-proton number fluctuations with the goal to detect the QCD critical end point and first-order phase transition. Interpreting these experimental signals requires a vital understanding of the interplay of critical phenomena and the nonequilibrium dynamics of the rapidly expanding fireball. We study these aspects with a fluid dynamic expansion coupled to the explicit propagation of the chiral order parameter sigma via a Langevin equation. Assuming a sigma-proton coupling through an effective proton mass, we relate cumulants of the order parameter and the net-proton number at freeze-out and obtain observable cumulant ratios as a function of beam energy. We emphasize the role of the nonequilibrium first-order phase transition where a mixed phase with gradual freeze-out can significantly alter the cumulants. We find that the presence of a critical end point is clearly visible in the cumulant ratios for a relatively wide range of center-of-mass energies.
