"QCD and the Standard Model in the Low-Energy, Non-Perturbative Regime"

“QCD 和低能、非微扰状态下的标准模型”

• 批准号: 126765-2012
• 负责人: Maltman, Kim
• 金额: $ 3.35万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=593371
• 关键词: QCD; Standard; Model; Low; Energy

All current evidence points to the Standard Model of particle physics as being the correct basic theory needed to describe all low-energy phenomena in the universe. In the Standard Model, the strong interactions (which are responsible, for example, for binding neutrons and protons into atomic nuclei) are described using Quantum Chromodynamics (QCD), while the weak and electromagnetic interactions are described using the unified electroweak theory of Glashow, Weinberg and Salam. Understanding the precise implications of the Standard Model, at low energies, for hadronic systems (those which feel the strong interactions) turns out to be a difficult task, for technical reasons associated with the strength of the strong interactions at these scales. The strength of the interactions complicates technical calculations for all processes at these scales involving hadrons. This is true not just for processes mediated by the strong interactions, but also for those mediated by weak and electromagnetic interactions in hadronic stystems, since the latter are altered in a non-trivial way by the strong force through quantum corrections. In this proposal, a number of computational techniques (such as "QCD sum rules", "Chiral Perturbation Theory" and "lattice gauge theory") will be employed to (i) produce quantitative predictions for hadronic properties and processes and (ii) allow precision determinations of a number of the basic parameters of the Standard Model. This work is of importance for improving our knowledge of the values of the Standard Model parameters (which parameters represent fundamental properties of our universe), for furthering our quantitative understanding of the effects of QCD in the strongly-interacting regime, and for providing enhancements to the repertoire of technical tools available to researchers studying strongly-interacting theories in general in future.

目前所有的证据都表明粒子物理学的标准模型是描述宇宙中所有低能现象所需的正确的基本理论。在标准模型中，强相互作用（例如，将中子和质子结合成原子核）是用量子色动力学（QCD）来描述的，而弱相互作用和电磁相互作用则是用希豪、温伯格和萨拉姆的统一电弱理论来描述的。理解低能强子系统（感受到强相互作用的系统）的标准模型的精确含义是一项艰巨的任务，因为技术原因与这些尺度上强相互作用的强度有关。相互作用的强度使得在这些尺度上涉及强子的所有过程的技术计算变得复杂。这不仅适用于强相互作用介导的过程，也适用于强子系统中由弱相互作用和电磁相互作用介导的过程，因为后者通过量子修正被强作用力以非平凡的方式改变。在这个提议中，一些计算技术（如“QCD求和规则”，“手征微扰理论”和“格点规范理论”）将被用来（i）产生强子性质和过程的定量预测和（ii）允许精确确定标准模型的一些基本参数。这项工作对于提高我们对标准模型参数值（这些参数代表了我们宇宙的基本性质）的认识，对于进一步定量地理解强相互作用机制中QCD的影响，以及对于增强未来研究强相互作用理论的研究人员可用的技术工具库具有重要意义。