Title: QCD at Fixed Topology Show Chinese title

Title: QCD 在固定拓扑结构下

Abstract: Since present Monte Carlo algorithms for lattice QCD may become trapped in a fixed topological charge sector, it is important to understand the effect of calculating at fixed topology. In this work, we show that although the restriction to a fixed topological sector becomes irrelevant in the infinite volume limit, it gives rise to characteristic finite size effects due to contributions from all $\theta$-vacua. We calculate these effects and show how to extract physical results from numerical data obtained at fixed topology. Show Chinese abstract

Abstract: 由于目前的格点QCD蒙特卡洛算法可能会被困在固定的拓扑荷扇区中，因此理解在固定拓扑下计算的影响是很重要的。 在这项工作中，我们表明尽管在无限体积极限下，限制在固定的拓扑扇区变得无关紧要，但由于所有 $\theta$-真空的贡献，它会导致特有的有限尺寸效应。 我们计算了这些效应，并展示了如何从在固定拓扑下获得的数值数据中提取物理结果。