Bound State Theory and High Precision QED: Muonium, Positronium, Hydrogen, and Pentaquarks

物理学中一个活跃的基础研究领域是类氢原子和奇异原子的研究，在这些原子中，一个粒子(如电子)被另一个粒子(如介子)取代。对这些系统性质的理论研究代表了本项目的主要目标。近年来，这一领域的实验精度达到了前所未有的水平，对理论的挑战越来越强烈。为了应对这一挑战，该项目将为以更高精度确定许多基本物理常数提供理论投入，如电子-Muon和电子-质子质量比、质子电荷半径和里德堡常数。这里发展的新的理论理解将用于下一次基本物理常数的CODATA分析。CODATA对基本常数的汇编被用于每个科学课堂，以及从基础研究到消费电子产品的许多科学和工程领域。该项目还将对五夸克的性质提供理论上的见解，五夸克是欧洲核研究组织(CERN)的LHCb合作最近发现的五个夸克的束缚态。参与这项研究的研究生和本科生将获得研究、计算机、解决问题和陈述的技能。高精度类氢束缚态量子电动力学是理论研究的一个活跃领域，既有近年来取得的惊人实验进展，也有内在的智力挑战。尽管在类氢轻束缚态理论方面取得了重大进展，但仍有一些具有挑战性的问题仍然存在，并将在本研究中得到解决：1)完全计算所有三环辐射-反冲修正对正电子超精细分裂的修正；2)完全计算由于双环辐射插入双光子交换非湮没图中费米子谱线对正电子超精细分裂的硬三环修正；3)完全计算所有相关的三环非反冲修正对氢和µ素的Lamb位移的影响。以上是原子物理学中兰姆跃迁最大的未知贡献。还将分别计算氢和钚的超精细分裂的三环无反冲修正。PI将进一步发展五夸克的氢离子解释。该项目将对它们的特性进行量化描述。

An area of active fundamental research in physics is the study of the hydrogen-like atoms and exotic atoms, atoms where one particle such as an electron is replaced by another such as a muon. Theoretical research of the properties of these systems represents the main goal of this project. In recent years, experiments in this area have reached an unprecedented level of accuracy, challenging the theory at a stronger and stronger level. Responding to this challenge, this project will provide theoretical input to the determination with higher precision of many fundamental physical constants, such as the electron-muon and electron-proton mass ratios, the proton charge radius, and the Rydberg constant. The new theoretical understanding developed here will be used in the next CODATA analysis of the fundamental physical constants. CODATA compilations of the fundamental constants are used in every science classroom, as well as in numerous fields of science and engineering, from fundamental research to consumer electronics. This project will also provide theoretical insight in the properties of pentaquarks, the bound states of five quarks recently discovered by the LHCb Collaboration at the European Organization for Nuclear Research (CERN). Graduate and undergraduate students participating in this research will acquire research, computer, problem solving, and presentation skills. High precision quantum electrodynamics of hydrogen-like bound states is an active field of theoretical research motivated both by the spectacular experimental progress achieved in recent years and the intrinsic intellectual challenge. Despite significant progress in the theory of light hydrogen-like bound states, a number of challenging problems remain and will be addressed in this research: 1) Complete calculation of all three-loop radiative-recoil corrections to hyperfine splitting in muonium, 2) Complete calculation of hard three-loop corrections to hyperfine splitting in positronium due to two-loop radiative insertions in the fermion lines in two-photon exchange nonannihilation diagrams, 3) Complete calculation of all relevant three-loop nonrecoil corrections to the Lamb shift in hydrogen and muonium. The above represent the largest unknown contributions to the Lamb shift in atomic physics. Respective three-loop nonrecoil corrections to hyperfine splitting in hydrogen and muonium will be calculated also. The PI will further develop the hadrocharmomium interpretation of pentaquarks. The project will provide quantitative description of their properties.