论文标题
夸克 - 梅森$σ$ - 模型中手性相变的动力学
Kinetics of the chiral phase transition in a quark-meson $σ$-model
论文作者
论文摘要
在这项研究中，开发了2PI有效行动形式主义对数值方法中进出平衡系统的系统形式主义的有效描述，从而可以通过考虑最轻，最相关的自由度来近似QCD的复杂性。特别是，当相位过渡发生在临界点附近，甚至当相位过渡是第一阶的，尽管初始系统是用纯粹的高斯净值准备在临界点上，否则正在证明，暂时建立了由四阶累积累积（或重新缩放的尺寸）编码的净 - 巴里昂数字的波动。这是不断发展的慢速和关键顺序参数的结果，即$σ$ - 场。另一方面，取决于（哈勃 - ）扩展量表的速度，这是由于介子，夸克和反夸克之间的碰撞而引起的最终耗散演化，并且顺序场大大削弱了最终波动。
In this study an effective description in the 2PI effective-action formalism for systems of quarks and mesons in and out of equilibrium within a numerical approach is developed, allowing to approximate the complexity of QCD by taking only the lightest and most relevant degrees of freedom into account. In particular the temporarily building up of fluctuations of the net-baryon number encoded by the fourth-order cumulant (or the rescaled curtosis) for lower momenta is being demonstrated when the phase transition occurs near the critical point, or even stronger when the phase transition is of first order, although the initial system is prepared with purely Gaussian fluctuations in the net baryon number. This is the result of the evolving slow and critical order parameter, i.e., the $σ$-field. On the other hand, depending on the speed of the (Hubble-)expansion scale, the final dissipative evolution due to the collisions among the mesons, the quarks and anti-quarks and the order field weakens the final fluctuations considerably.
