Novel phenomenological applications of light-front QCD

光锋 QCD 的新颖唯象应用

• 批准号: SAPIN-2021-00038
• 负责人: Ahmady, Mohammad
• 金额: $ 1.75万
• 依托单位: Mount Allison University
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743111
• 关键词: Novel; phenomenological; applications; light; front

This research helps with our better understanding of the structure of matter. The bulk of matter is made of quarks, which in the Standard Model (SM) are the fundamental constituents of hadrons like protons and neutrons. Quantum Chromodynamics (QCD) is the widely accepted theory of interactions between quarks which proceeds via the exchange of gluons, the elementary force carriers of the strong force. According to QCD, the attractive force between quarks increases with distance and therefore quarks are confined within bound states with other quarks and antiquarks. Indeed, theoretical calculations based on QCD in long quark distance domain is only possible through numerical simulations and the regular application of the perturbation technique cannot work. Consequently, to get analytical insight into the properties of the bound state of quarks, one has to resort to models for QCD in the strong coupling regime. One such models is based on a duality proposed around two decades ago by Juan Maldacina who showed the mathematical equivalence of a strongly interacting theory in 4-dimensonal space-time to a weakly interacting gravitational theory in a higher dimensional space-time. This model is referred to as light-front holographic QCD. My proposed research is to use this model to make predictions for a wide variety of physical observables which are/will be observed experimentally and compare notes with predictions obtained from other widely used models. Our theoretical predictions are relevant to many experimental facilities around the world like, the BELLE II detector at SuperKEKB Collider (located at KEK, Japan), the Large Hadron Collider (LHC), which its Run III is expected to start in 2021 as well the past experiments at HERA at DESY (located in Germany) and JLab in the US. Through this exercise, we learn how holographic QCD should be augmented when applied to different "flavors" of quarks and at the same time find out the model dependence of our theoretical calculations. The latter is an important piece in testing the SM and looking for signals of new physics and is beyond the domain of SM. This research involves students and contributes to the training of the next generation of Canadian scientist by expanding their knowledge of subatomic physics and elevating their computational skills. In this way, we create opportunities for young researchers to participate in a field that they have previously felt formidable and out of reach.

这项研究有助于我们更好地理解物质的结构。大部分物质是由夸克组成的，在标准模型（SM）中，夸克是强子（如质子和中子）的基本组成部分。量子色动力学（QCD）是广泛接受的夸克之间的相互作用理论，通过胶子的交换进行，胶子是强力的基本力载体。根据QCD，夸克之间的吸引力随着距离的增加而增加，因此夸克被限制在与其他夸克和反夸克的束缚态中。事实上，基于长夸克距离域的QCD理论计算只能通过数值模拟来实现，而常规的微扰技术是无法实现的。因此，要分析了解夸克束缚态的性质，就必须求助于强耦合体系中的QCD模型。一个这样的模型是基于大约20年前胡安·马尔达西纳提出的对偶性，他证明了四维时空中的强相互作用理论与高维时空中的弱相互作用引力理论的数学等价性。这种模型被称为光前全息QCD。我建议的研究是使用这个模型来预测各种各样的物理观测值，这些物理观测值是/将通过实验观察到的，并与其他广泛使用的模型的预测进行比较。我们的理论预测与世界各地的许多实验设施有关，如SuperKEKB对撞机（位于日本KEK）的贝儿II探测器，大型强子对撞机（LHC），其运行III预计将于2021年开始，以及DESY（位于德国）HERA和美国JLab的过去实验。通过这个练习，我们了解了全息QCD在应用于不同“口味”的夸克时应该如何被增强，同时找出我们的理论计算的模型依赖性。后者是测试SM和寻找新物理信号的重要部分，并且超出了SM的范围。 这项研究涉及学生，并有助于通过扩大他们的亚原子物理学知识和提高他们的计算技能来培训下一代加拿大科学家。通过这种方式，我们为年轻的研究人员创造了参与他们以前感到强大和遥不可及的领域的机会。