Study of Lattice QCD by numerical simulations including dynamical quark effects

通过包括动态夸克效应在内的数值模拟研究晶格 QCD

• 批准号: 11640294
• 负责人: OKAWA Masanori
• 金额: $ 1.86万
• 依托单位: HIROSHIMA UNIVERSITY (2001-2002)The High Energy Accelerator Research Organization (1999-2000)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640294/
• 关键词: Lattice QCD; Hadron matrix element; dynamical quark; Lattice QCD; Hadron matrix element; dynamical quark

Including dynamical quark loop effects in lattice QCD simulations is one of the most important problem to make quantitative study of strong interaction and to obtain phenomenologically important hadron matrix elements. In fact it has been shown that in the quenched approximation where the dynamical quark loop effect is neglected the evaluated hadron mass spectrums deviate from experimental values by about 10%. For N_f = 2 QCD where the dynamical u and d quark effects are taken into account we have made large scale simulations with the exact hybrid Monte Carlo (HMC) simulation algorithm. It has been shown that a large part of the deviation in hadron mass spectrum observed in the quenched approximation disappears with the inclusion of N_f = 2 dynamical quark effect. In the real world, however, there are three light quarks and it is important to make simulations including the s quark loop effect. For this purpose we have developed efficient exact simulation algorithm for odd number of O(a) improved Wilson fermions. We have made first realistic N_f = 3 QCD simulation with O(a) improved Wilson fermions and estimated mass spectrum for various hadrons, from which fundamental lattice QCD parameters such as lattice spacing and quark masses are determined.

在晶格QCD模拟中包括动态夸克环效应是对强相互作用进行定量研究并获得现象学重要的强子基质元素的最重要问题之一。实际上，已经表明，在淬灭的近似中，动态夸克环效应被忽略了评估的强子质谱与实验值偏离约10％。对于N_F = 2 QCD，其中考虑了动态U和D夸克效应，我们已经使用精确的混合蒙特卡洛（HMC）模拟算法进行了大规模模拟。已经表明，随着n_f = 2动态夸克效应的包含，在淬灭近似中观察到的强子质谱中的大部分偏差消失。但是，在现实世界中，有三个轻夸克，进行模拟包括s夸克循环效应很重要。为此，我们开发了有效的精确仿真算法，以改善o（a）改进的威尔逊费米子。我们首先实现了n_f = 3 QCD模拟，o（a）改进了威尔逊·费米子（A）的各种载体，并估计了质谱，从中确定了基本的晶格QCD参数，例如晶格间距和夸克质量。