arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0903.3598hep-lathep-ph
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改进交错夸克2+1味的全非微扰QCD模拟

Full nonperturbative QCD simulations with 2+1 flavors of improved staggered quarks

A. Bazavov, C. Bernard, C. DeTar, Steven Gottlieb, U. M. Heller, J. E. Hetrick, J. Laiho, L. Levkova, P. B. Mackenzie, M. B. Oktay, R. Sugar, D. Toussaint, R. S. Van de Water

摘要:

在过去的十年中,量子色动力学(QCD)的数值研究取得了巨大的进展,通过使用改进的格点QCD公式(改进的作用量),新算法的开发和格点规范理论家可用的计算能力的快速增长。在这篇文章中,我们描述了使用改进的交错夸克形式主义,“asqtad”费米子模拟全QCD。这些模拟是用两种简并的轻夸克(上夸克和下夸克)和一种较重的夸克(奇异夸克)进行的。几个轻夸克质量,下至约3倍的物理轻夸克质量,和六个晶格间距已被使用。这使得许多低能QCD观测的可控连续谱和手征外推成为可能。我们回顾了改进的交错形式主义,强调的优点和缺点。特别是,我们审查的过程中删除不需要的交错物种的连续极限。然后,我们描述了由MILC协作创建的asqtad晶格合奏。所有的MILC格点系综都是公开可用的,并且它们已经被许多格点规范理论团体广泛使用。我们回顾了用它们获得的物理结果,并讨论了这些结果对唯象学的影响。内容包括重夸克势、轻强子的光谱、夸克质量、轻和重轻赝标介子的衰变常数、半轻子形状因子、核子结构、散射长度等。最后,我们简要介绍一下非常有前途的未来前景。

英文摘要:

Dramatic progress has been made over the last decade in the numerical study of quantum chromodynamics (QCD) through the use of improved formulations of QCD on the lattice (improved actions), the development of new algorithms and the rapid increase in computing power available to lattice gauge theorists. In this article we describe simulations of full QCD using the improved staggered quark formalism, ``asqtad'' fermions. These simulations were carried out with two degenerate flavors of light quarks (up and down) and with one heavier flavor, the strange quark. Several light quark masses, down to about 3 times the physical light quark mass, and six lattice spacings have been used. These enable controlled continuum and chiral extrapolations of many low energy QCD observables. We review the improved staggered formalism, emphasizing both advantages and drawbacks. In particular, we review the procedure for removing unwanted staggered species in the continuum limit. We then describe the asqtad lattice ensembles created by the MILC Collaboration. All MILC lattice ensembles are publicly available, and they have been used extensively by a number of lattice gauge theory groups. We review physics results obtained with them, and discuss the impact of these results on phenomenology. Topics include the heavy quark potential, spectrum of light hadrons, quark masses, decay constant of light and heavy-light pseudoscalar mesons, semileptonic form factors, nucleon structure, scattering lengths and more. We conclude with a brief look at highly promising future prospects.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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