High precision calculations in quantum field theory

量子场论的高精度计算

• 批准号: 355373-2011
• 负责人: Penin, Alexander
• 金额: $ 4.81万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549712
• 关键词: precision; calculations; quantum; field; theory

The following decade is crucial for our understanding of the fundamental structure of elementary particles and forces. Large Hadron Collider (LHC) is already collecting data which will give access to a completely new energy domain and could in a nearest future uncover principally new phenomena such as the extra space dimensions, supersymmetry, etc. On the other hand increasing accuracy of the low-energy experiments makes possible a very accurate determination of the fundamental parameters of the standard model of particle interactions and becomes competitive in probing new physics beyond the standard model. In most cases the new physics shows up as a tiny deviation from the theoretical predictions based on the standard model. Thus the high precision of the predictions becomes mandatory. The main goal of the project is the calculation of the high order perturbative corrections in a wide class of the quantum field theory problems ranging from nonrelativistic threshold to ultrarelativistic Sudakov limit, which are of primary phenomenological importance for current and future experiments. This includes in particular the electroweak radiative corrections to the electron-positron scattering, which is the ``standard candle'' for electron-positron colliders, the strong coupling radiative corrections to the top-antitop threshold production and to the properties of the bottomonium states, high order analysis of quarkonium and positronium hyperfine splitting. Possible phenomenological applications of the results include precise determination of the heavy quark masses and strong coupling constant. The difficulty of the problems requires developing new theoretical and computational tools which are closely related to the fundamental concepts of the quantum field theory such as the effective field theory approach, renormalization group, etc. Deeper understanding and development of these concepts and possible application of the field theory methods in condensed matter physics are also among the goals of the project.

接下来的十年对于我们理解基本粒子和力的基本结构至关重要。大型强子对撞机（LHC）已经在收集数据，这些数据将提供进入全新能量域的机会，并可能在不久的将来发现主要的新现象，例如额外空间维度、超对称性等。另一方面，低能实验准确性的提高使得非常准确地确定粒子相互作用标准模型的基本参数成为可能，并且在探索标准模型之外的新物理方面具有竞争力。在大多数情况下，新物理学与基于标准模型的理论预测存在微小偏差。因此，高精度的预测就成为强制性的。该项目的主要目标是计算从非相对论阈值到超相对论苏达科夫极限的各种量子场论问题的高阶微扰校正，这对于当前和未来的实验具有主要的现象学重要性。这特别包括对电子-正电子散射的电弱辐射校正，这是电子-正电子对撞机的“标准烛光”，对顶-反顶阈值产生和底态性质的强耦合辐射校正，夸克素和正电子素超精细分裂的高阶分析。结果可能的唯象应用包括重夸克质量和强耦合常数的精确测定。这些问题的难度需要开发新的理论和计算工具，这些工具与量子场论的基本概念密切相关，如有效场论方法、重正化群等。对这些概念的更深入理解和发展以及场论方法在凝聚态物理中的可能应用也是该项目的目标之一。