Nicht-perturbative Analyse von Effekten der starken Wechselwirkung, durch numerische Simulationen auf dem Gitter

通过网格数值模拟对强相互作用效应进行非微扰分析

• 批准号: 5442439
• 负责人: Dr. Thomas Chiarappa
• 金额: --
• 依托单位: Dipartimento di Fisica
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5442439?language=en
• 关键词: Nicht; perturbative; Analyse; von; Effekten

Our project is concerned with the investigation of non-perturbative aspects of Quantum ChromoDynamics (QCD), the field theory that is believed to describe strong interaction between elementary particles. In particular, we consider the theory regularised in a gauge invariant way on the lattice, where non-perturbative computations are feasible by means of Monte Carlo simulations. We will focus our attention on the theoretical evaluation of quantities relevant for the phenomenology of the Standard Model, such as Low Energy Constants of Chiral Perturbation Theory and matrix elements of the effective weak Hamiltonian operator, which are dominated by non-perturbative QCD contributions. We plan to simulate two different ultraviolet regularisations of the quark fields: chirally twisted Wilson fermions (twisted mass) and the overlap realization of chirally invariant Ginsparg - Wilson fermions (for small volumes). We also are going to improve algorithmic techniques relevant for: efficient computations with overlap fermions, initially still in the quenched approximation (i.e. without sea quark effects); unquenched simulations of fermions, in a first stage limited to the computationally less expensive formulation with chirally twisted Wilson fermions.

我们的项目涉及对量子染色体动力学（QCD）的非扰动方面的研究，量子染色体动力学（QCD）被认为描述了基本颗粒之间的强烈相互作用。特别是，我们考虑以规格不变的方式在晶格上进行规范的理论，在该理论中，通过蒙特卡洛模拟，非扰动计算是可行的。我们将注意力集中在与标准模型现象学相关的数量的理论评估上，例如手性扰动理论的低能常数和有效的弱汉密尔顿操作员的矩阵元素，这些元素由非驱动QCD贡献所支配。我们计划模拟夸克场的两个不同的紫外线正规化：手性扭曲的威尔逊费米斯（扭曲的质量）和手性不变的人参的重叠实现 - 威尔逊·费米斯（对于少量）。我们还将改善与以下算法相关的算法技术：具有重叠费用的有效计算，最初仍处于淬火近似中（即没有海夸克效应）；在第一阶段中，毫无疑问的fermions模拟限制在计算较便宜的配方中，威尔逊·费米斯（Wilson Fermions）。