标题： 格点QCD中拓扑易感性中的离散化效应 显示英文标题

标题： Discretisation effects in the topological susceptibility in lattice QCD

摘要： 我们研究了具有两个夸克 flavour 的 QCD 中的拓扑易感性 χ，使用了通过 O(a)- 改进的 clover 夸克作用产生的格点场构型。我们发现了小夸克质量 mq 下预期抑制的明确证据，并检查了$\chi$随此质量和晶格间距 a 的变化。联合连续极限和 chiral 拓展与理论预期一致，当 (a, mq) -> 0 时。在更具 chiral 的集合上观察到自相关性适度增加，但仍在较大的统计误差范围内。对于 Leutwyler-Smilga 参数 x_LS > 10，有限体积效应可以忽略不计，且未观察到附近相变的证据。 显示英文摘要

摘要： We study the topological susceptibility, chi, in QCD with two quark flavours using lattice field configurations that have been produced with an O(a)-improved clover quark action. We find clear evidence for the expected suppression at small quark mass, m_q, and examine the variation of $\chi$ with this mass and the lattice spacing, a. A joint continuum and chiral extrapolation yields good agreement with theoretical expectations as (a, m_q) -> 0. A moderate increase in autocorrelation is observed on the more chiral ensembles, but within large statistical errors. Finite volume effects are negligible for Leutwyler-Smilga parameter x_LS > 10, and no evidence for a nearby phase transition is observed.