Development of Research on the Standard Model on the Lattice using the Massively Parallel Computer CP-PACS

利用大规模并行计算机CP-PACS进行格子标准模型研究进展

• 批准号: 09304029
• 负责人: IWASAKI Yoichi
• 金额: $ 20.8万
• 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: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09304029/
• 关键词: numerical simulation; parallel computer; CP-PACS; lattice QCD; hadron; quenched approximation; full QCD; improved lattice action; 数値シュミレーション; 改良された作用; 有限温度QCD; 相転移; フレーバー

This research program aimed to exploit the high computational power of the CP-PACS computer for significantly advancing the study of the non-perturbative aspects of the Standard Model using the lattice formulation of QCD. Specifically, we concentrated on the following subjects :(i) To obtain precise light hadron spectrum in quenced lattice QCD, we carried out an extensive simulation with the standard plaquette gauge action and the Wilson quark action employing large lattices and high statistics. For the first time, we clearly showed that the quenched light hadron spectrum deviates from the experiment by about 10% due to the quenched approximation.(ii) From a systematic study of full GCD with two flavors of light dynamical quarks using an improved action, we showed that the hadron spectrum becomes much closer to experiment than the quenched approximation. The values for light quark masses from full QCD are 20-30% smaller than those in the quenched QCD. The decay constant for B and Bs me … More sons, which are important in a study of the weak interaction, is larger by about 10% in full QCD. The η' meson mass in the continuum limit is close to the experiment, suggesting that the U(1) problem is solved in QCD.(iii) We studied the finite-temperature phase transition and equation of state of QCD using the same improved action as employed in (ii). For the pure gluon theory, we found that the equation of state in the continuum limit agrees well with that obtained with the standard action, demonstrating high reliability of our methods. This work has been extended to full QCD with two flavors of quarks. The phase structure was explored and the equation of state was calculated on an NィイD2tィエD2 = 4 lattice.(iv) Domain-wall QCD offers a possibility to resolve the problem of broken chiral symmetry in the conventional formulations of lattice quarks. As a first step to establish its viability, we studied chiral properties as a function of various parameters of the formalism. We found that exact chiral symmetry is realized for sufficiently fine lattices, while the formalism does not work on coarse lattices. Here, an improved gauge action shows improved chiral symmetry. Work is now extended to calculations of physical matrix elements relevant for CP violation studies. Less

该研究计划旨在利用CP-PACS计算机的高计算能力，使用QCD的晶格公式显着推进标准模型的非微扰方面的研究。具体而言，我们集中在以下几个方面：（i）为了获得精确的轻强子谱，我们采用大格点和高统计量，对标准格点规范作用量和Wilson夸克作用量进行了广泛的模拟。我们第一次清楚地表明，由于猝灭近似，猝灭轻强子谱偏离实验约10%。(ii)通过对两种光动力学夸克的全GCD的系统研究，我们发现强子谱比猝灭近似更接近实验。全QCD的轻夸克质量值比猝灭QCD的轻夸克质量值小20-30%。B和Bs的衰变常数 ...更多信息 在弱相互作用研究中很重要的子，在完整的QCD中大约大10%。在连续极限下的η'介子质量与实验结果接近，表明U（1）问题在QCD中得到了解决。(iii)我们用与（ii）中相同的改进作用量研究了QCD的有限温度相变和状态方程。对于纯胶子理论，我们发现在连续极限下的状态方程与标准作用量下的状态方程吻合得很好，表明我们的方法具有很高的可靠性。这一工作已推广到具有两种夸克的全QCD。探讨了相结构，状态方程计算上的N D2 t D2 = 4晶格。(iv)畴壁QCD为解决传统格夸克表述中的手征对称性破缺问题提供了可能。作为建立其可行性的第一步，我们研究了手性性质作为各种参数的函数的形式主义。我们发现，精确的手征对称性是实现足够细的晶格，而形式主义不工作的粗糙晶格。在这里，改进的规范作用表现出改进的手征对称性。现在的工作扩展到计算的物理矩阵元素有关的CP违反的研究。少

项目成果

Y. Iwasaki: "The CP-PACS Project and Computational Physics1"Proc. International Symposium on "Parallel Computing in Engineering and Science", Science and Technology Agency. 1 (1997)

Y. Iwasaki：“CP-PACS 项目和计算物理1”Proc。

S. Aoki, Y. Iwasaki, K. Kanaya, S. Kaya, A. Ukawa, and T. Yoshi＼'e: "Finite-temperature chiral transitions in QCD with the Wilson quark action"Nucl. Phys. B (Proc. Suppl.). 63. 397-399 (1998)

S. Aoki、Y. Iwasaki、K. Kanaya、S. Kaya、A. Ukawa 和 T. Yoshie：“威尔逊夸克作用下的 QCD 有限温度手性跃迁”（Proc. B）。补编）。63。397-399（1998）

S. Aoki, K. Nagai, S. V. Zenkin: "Lattice fermions with Majorana couplings"Nucl. Phys. B (Proc. Suppl.). 63. 602-604 (1998)

S. Aoki、K. Nagai、S. V. Zenkin：“具有马约拉纳耦合的晶格费米子”Nucl。

Y. Iwasaki, K. Kanaya, S. Sakai and T. Yoshi＼'e: "Quantum Chromodynamics with Many Flavors"Prog. Theor. Phys. Suppl.. 131. 415-426 (1998)

Y. Iwasaki、K. Kanaya、S. Sakai 和 T. Yoshi＼e：“多种风味的量子色动力学”Prog。 131. 415-426 (1998)

Y. Taniguchi, A. Ukawa: "Perturbative calculation of improved coefficients to $O(g^2a)$ for bilinear quark operators in lattice QCD"Phys. Rev. D. 58. ref.114503,1-8 (1998)

Y. Taniguchi、A. Ukawa：“晶格 QCD 中双线性夸克算子的改进系数的微扰计算为 $O(g^2a)$”Phys。