论文标题
背景磁场中三个风味QCD的手性相结构
Chiral phase structure of three flavor QCD in a background magnetic field
论文作者
论文摘要
我们使用标准交错动作和Wilson Plaquette Gauge动作研究了背景$ U（1）$磁场中三个风味QCD的手性相结构。我们在晶格上进行仿真$n_τ= 4 $，四个空间范围为$n_σ= 8,16、20 $和24。我们选择了一个小于晶格间距的小夸克夸克质量为$ am = 0.030 $，因此在磁场上有两个值的交叉过渡，并在消失的磁场上有一个compac的compact of a pack in nmage nmage in Mainge of a pack in n of a pack in n latte conte contect of a pack in contect of a pack in contect of a pack in contect of a pack in contect of a pack in n pack in n pack。 e {b}} \ simeq 1.5 $和2。我们发现，在存在背景磁场的情况下，过渡变得更强，并从订单参数易感性的体积缩放以及手势冷凝物的时间历史中的亚稳态状态变成一阶。另一方面，即使在一阶相变的政权范围内，手性冷凝物和过渡温度也总是会随$ b $而增加。这表明，手性冷凝物和过渡温度的行为的差异是$ b $的函数，在较早的晶格研究之间使用具有标准交错的fermions的较大的晶格质子质量，而使用带有改善交错效率的物理培养的质量则主要是由于晶格临界值效应。
We investigate the chiral phase structure of three flavor QCD in a background $U(1)$ magnetic field using the standard staggered action and the Wilson plaquette gauge action. We perform simulations on lattices with a temporal extent of $N_τ=4$ and four spatial extents of $N_σ= 8,16, 20$ and 24. We choose a smaller-than-physical quark mass in lattice spacing as $am = 0.030$ such that there exists a crossover transition at vanishing magnetic fields, and adopt two values of magnetic field strength in lattice spacing $a \sqrt{ e{B}}\simeq 1.5$ and 2. We find that the transition becomes stronger in the presence of a background magnetic field, and turns into a first order as seen from the volume scaling of the order parameter susceptibility as well as the metastable states in the time history of the chiral condensate. On the other hand, the chiral condensate and transition temperature always increase with $B$ even within the regime of a first order phase transition. This suggests that the discrepancy in the behavior of chiral condensates and transition temperature as a function of $B$ between earlier lattice studies using larger-than-physical pion masses with standard staggered fermions and those using physical pions with improved staggered fermions is mainly due to lattice cutoff effects.
