Low-lying Dirac spectrum of staggered quarks
Low-lying Dirac spectrum of staggered quarks
复制标题
低位狄拉克交错夸克谱
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Q. Mason
中科院分区：
文献类型：
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作者：
E. Follana;A. Hart;C. Davies;Q. Mason
我们调查和澄清的作用，拓扑结构和周围的问题的交错夸克{π}-制度。我们研究了在猝灭格点QCD胶子背景下用Symanzik改进的胶子作用量产生的未改进和改进的交错夸克Dirac算符。对于改进的狄拉克算子，我们发现一个明确的分离的频谱到可能是零模式和其他。的数量将是零模式依赖于拓扑电荷的连续介质指数定理预测，和它们的手征性的期望值是最大的改进行动（{approx_equal}0.7）。其余的模式具有低的手征性，并显示出明显的迹象，集群成四重态，成为退化的连续极限。我们表明，晶格间距和体积依赖的本征值符合预期。此外，非零模式遵循随机矩阵理论预测的所有拓扑电荷部门。从理论分布拟合中提取的手征凝聚物的值彼此一致，并且与使用Banks-Casher关系从本征值的总密度获得的结果一致。我们的结论是，当费米子和规范作用量都得到改善时，交错夸克对QCD拓扑的响应是正确的。
We investigate and clarify the role of topology and the issues surrounding the {epsilon}-regime for staggered quarks. We study unimproved and improved staggered quark Dirac operators on quenched lattice QCD gluon backgrounds generated using a Symanzik-improved gluon action. For the improved Dirac operators we find a clear separation of the spectrum into would-be zero modes and others. The number of would-be zero modes depends on the topological charge as predicted by the continuum index theorem, and the expectation values of their chirality are large for the most improved actions ({approx_equal}0.7). The remaining modes have low chirality and show clear signs of clustering into quartets that become degenerate in the continuum limit. We demonstrate that the lattice spacing and volume dependence of the eigenvalues follow expectations. Furthermore, the nonzero modes follow the random matrix theory predictions for all topological charge sectors. The values of the chiral condensate extracted from fits to the theoretical distributions are consistent with each other, and with the results obtained from the total density of eigenvalues using the Banks-Casher relation. We conclude that staggered quarks respond correctly to QCD topology when both fermion and gauge actions are improved.