Bound State Theory in QED and QCD: Muonium and Pentaquarks

基本粒子的束缚态在自然界中普遍存在，是物理学中最有趣和最具挑战性的研究对象之一。本计画的主要目标为量子电动力学与量子色动力学中束缚态性质的理论研究。μ素是一种电子与正μ子的松散束缚态，对其性质的研究将减少μ素超精细分裂理论的不确定性。与日本正在进行的MuSEUM实验的结果一起，这将导致电子-μ子质量比的更精确值，将首次允许检测弱相互作用对原子能级能量移动的贡献，并将用于未来CODATA调整基本物理常数。隐魅五夸克是欧洲核子研究中心最近发现的一类新的强相互作用粒子，其研究目标是探索它们的内部结构。将进一步发展五夸克的强子粲偶素和分子方案，并将获得区分这些模型（量子数和质量）的预测，并与实验数据进行比较。这将导致在理解强相互作用动力学方面取得进展。对五夸克态的研究将是一个跨学科的研究，并将对粒子物理学领域做出贡献。类氢束缚态的高精度量子电动力学是一个活跃的理论研究领域，其动力来自于引人注目的实验进展和智力挑战。电磁束缚二粒子态理论中的许多理论问题，特别是μ素的理论问题，还需要进一步的研究。本研究的目的是减少理论误差（由于尚未计算的贡献）的超精细分裂的μ素低于10赫兹。为了实现这一目标，许多反冲修正的精细结构常数的第七阶和非反冲修正的精细结构常数的第八阶将被计算。在五夸克理论的工作中，将计算强子粲偶素和分子Pc（4312）的部分衰变宽度，将探索在这两种情况下对宽Pc（4380）共振的解释，以及在分子图像中对LHCb Pc（4440）和Pc（4457）五夸克的自然解释。在分子Pc（4312）五夸克态方面，该研究小组将寻找比π介子重的介子交换如何产生松散束缚共振的自然定性和定量解释。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Bound states of fundamental particles are ubiquitous in nature and are one of the most interesting and challenging objects of research in physics. Theoretical research on the properties of bound states in quantum electrodynamics and in quantum chromodynamics is the main goal of this project. Research on the properties of muonium, a loosely bound state of electron and positive muon, will reduce the theoretical uncertainty for the hyperfine splitting in muonium. Together with the results of the ongoing MuSEUM experiment in Japan, this will lead to a more precise value of the electron-muon mass ratio, will allow for the first time a detection of the weak interaction contribution to the energy shift of atomic energy levels, and will be used in the future CODATA adjustment of the fundamental physical constants. The goal of research on the hidden charm pentaquarks, a new class of strongly interacting particles recently discovered at CERN, is to explore their internal structure. The hadrocharmonium and molecular scenarios for pentaquarks will be developed further, and predictions that differentiate these models (quantum numbers and masses) will be obtained and compared with the experimental data. This will lead to progress in understanding of the strong interaction dynamics. The results of the research on pentaquarks will be cross-disciplinary and will contribute to the field of particle physics.High precision quantum electrodynamics of hydrogenlike bound states is an active field of theoretical research motivated both by the spectacular experimental progress and the intellectual challenge. Many theoretical problems in the theory of electromagnetically bound two-particle states, in particular of muonium, require further research. The objective of this research is to reduce the theoretical error (due to the yet uncalculated contributions) of the hyperfine splitting in muonium below 10 Hz. To achieve this goal, numerous recoil corrections of the seventh order in the fine structure constant and nonrecoil corrections of the eighth order in the fine structure constant will be calculated. In work on the theory of pentaquarks, partial decay widths of the hadrocharmonium and molecular Pc(4312) will be calculated, interpretation of the wide Pc(4380) resonance in both scenarios will be explored, as well as a natural interpretation of the LHCb Pc(4440) and Pc(4457) pentaquarks in the molecular picture. In connection with the molecular Pc(4312) pentaquark, the group will look for a natural qualitative and quantitative explanation of how exchanges by mesons heavier than the pion can generate a loosely bound resonance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.