标题： 物理夸克质量下格点QCD中的手征凝聚态和中性伪标量介子的屏蔽质量 显示英文标题

标题： Chiral condensates and screening masses of neutral pseudoscalar mesons from lattice QCD at physical quark masses

摘要： 我们研究了温度$T$和外加磁场$eB$对具有物理夸克质量的 (2+1)-味格点QCD中中性赝标介子的手征凝聚量和屏蔽质量的影响，其中包括$\pi^0$、$K^0$和$\eta_{s\bar{s}}^0$。手征凝聚量通过Ward-Takahashi恒等式与屏蔽质量内在相关，后者表征赝标道中空间关联长度的倒数。 使用高度改进的交错夸克，我们在时间维度大小为$N_\tau = 8, 12, 16$的格点上进行模拟，纵横比为4，覆盖从145 MeV到166 MeV的五个温度。 对于每种温度，模拟了八种磁场强度，最高达到$eB \sim 0.8$ GeV$^2$。 这些模拟使我们能够对手征凝聚和屏蔽质量提供连续性估计。 我们观察到，在轻夸克（$ud$）、奇异-轻夸克（$ds$）和奇异夸克（$s$）的凝聚量随着磁场和温度的变化表现出复杂的行为，反映了磁场催化与反磁场催化效应之间的竞争。 这种复杂行为也在中性伪标量介子的屏蔽质量中得到反映。 值得注意的是，$\pi^0$ 和 $K^0$ 的筛选质量对 $eB$ 表现出非单调依赖关系，与相应的手征凝聚量变化密切相关。 同时，$\eta_{s\bar{s}}^0$ 的筛选质量随着 $eB$ 的增加单调下降。 这些发现为理解热磁介质中的 QCD 行为提供了宝贵的见解，并可作为低能 QCD 模型和有效理论的基准。 显示英文摘要

摘要： We investigate the effects of temperature $T$ and external magnetic fields $eB$ on the chiral condensates and screening masses of neutral pseudoscalar mesons, including $\pi^0$, $K^0$, and $\eta_{s\bar{s}}^0$, in (2+1)-flavor lattice QCD with physical quark masses. The chiral condensates are intrinsically connected to the screening masses via Ward-Takahashi identities, with the latter characterizing the inverse of the spatial correlation length in the pseudoscalar channel. Using highly improved staggered quarks, we perform simulations on lattices with temporal extents $N_\tau = 8, 12, 16$ and an aspect ratio of 4, covering five temperatures from 145 MeV to 166 MeV. For each temperature, eight magnetic field strengths are simulated, reaching up to $eB \sim 0.8$ GeV$^2$. These simulations allow us to provide continuum estimates for the chiral condensates and screening masses. We observe intricate behavior in the light ($ud$), strange-light ($ds$) and strange ($s$) quark condensates as functions of the magnetic field and temperature, reflecting the competition between magnetic catalysis and inverse magnetic catalysis effects. This complex behavior is also mirrored in the screening masses of the neutral pseudoscalar mesons. Notably, the screening masses of $\pi^0$ and $K^0$ exhibit a non-monotonic dependence on $eB$, closely following the variations in their corresponding chiral condensates. Meanwhile, the screening mass of $\eta_{s\bar{s}}^0$ decreases monotonically with increasing $eB$. These findings provide valuable insights for understanding the behavior of QCD in a thermomagnetic medium and can serve as benchmarks for low-energy QCD models and effective theories.