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Study of the Standard Model on the Lattice with Massively Parallel Computer CP-PACS

大规模并行计算机CP-PACS格上标准模型的研究

基本信息

批准号：
15204015
负责人：
UKAWA Akira
金额：
$ 30.37万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15204015/
关键词：
lattice gauge theory lattice quantum chromodynamics numerical simulation quarks and gluons phase transition strong interactions Monte Carlo methods perturbation theory 格子QCD クォーククローバー作用

项目摘要

This project carried out an extensive Nf=2+1 lattice QCD simulation including dynamical effects of all three light quarks, u, d, s using the fully O(a) improved Wilson-clover quark action and RG-improved gluon action at three lattice spacings a=0.071fm, 0.1fm and 0.12fm. Detailed study was made of the light hadron spectrum, light quark masses and heavy quark physics, taking a systematic continuum extrapolation. The main results are as follows :(1) Light hadron spectrumIn quenched QCD a systematic deviation of up to 10% is known to exist in the meson and baryon spectrum. The present calculation has shown that this deviation goes away in the Nf=2+1 calculations, the results showing an agreement with experiment at a 1% level. Systematic errors, however, arising from the fact that quarks are still relatively heavy in the simulations need to be assessed using Wilson chiral perturbation theory. Preliminary analyses show that they are consistent with polynomial extrapolation.(2) Light quark m … More assesThe meson spectrum results allow us to evaluate the light quark masses, for which we find in the continuum limit, m=3.49(15)MeV for the average of u and d quark mass in the MS scheme at μ=2GeV, and m=90.9(3.7)MeV for s quark. These values are about 2/3 of the phenomenologically widely used values.(3) Heavy quark physicsExtensive tests were made of the relativistic heavy quark action proposed by the members of the project. Test calculations in quenched QCD for the bottomonium spectrum and B meson decay constants with a non-perturbative tuning of speed of light showed excellent scaling behavior. Encouraged by the success, calculations on the dynamical Nf=2+1 flavor configurations are being made.(4) Future perspectiveThe results obtained in this project have been presented at Lattice Symposia and various international conferences. A limitation encountered in the present calculation is difficulty of penetrating into the light quark mass region. Application of the domain-decomposed HMC algorithm recently proposed has been tested, and encouraging results were obtained for their use on the next generation PACS-CS computer. Less

本项目进行了广泛的Nf=2+1晶格QCD模拟，包括使用完全O(a)改进的Wilson-clover夸克作用和rg改进的胶子作用在三个晶格间距a=0.071fm， 0.1fm和0.12fm下的三种轻夸克，u, d， s的动力学效应。采用系统的连续统外推方法，对轻强子谱、轻夸克质量和重夸克物理进行了详细的研究。主要结果如下：(1)光强子谱在猝灭QCD中，介子和重子谱存在高达10%的系统偏差。本计算表明，这种偏差在Nf=2+1计算中消失，结果与实验在1%的水平上一致。然而，由于夸克在模拟中仍然相对较重而引起的系统误差需要使用威尔逊手性微扰理论来评估。初步分析表明，它们符合多项式外推法。(2)轻夸克m…More的计算：根据介子谱的结果，我们可以计算出轻夸克的质量，在连续体极限下，μ=2GeV时，u和d夸克的平均质量m=3.49(15)MeV， s夸克的平均质量m=90.9(3.7)MeV。这些值大约是现象学上广泛使用的值的2/3。(3)重夸克物理对项目成员提出的相对论性重夸克作用进行了大量的测试。在淬灭QCD中对底溴铵光谱和B介子衰变常数进行了测试计算，并对光速进行了非微扰调整，结果显示出良好的标度行为。受到成功的鼓舞，人们正在计算动态的Nf=2+1风味配置。(4)未来展望本项目取得的成果已在莱迪思研讨会和各种国际会议上发表。在目前的计算中遇到的一个限制是难以穿透到轻夸克质量区域。本文对提出的域分解HMC算法进行了应用测试，取得了令人鼓舞的结果，可用于下一代PACS-CS计算机。少