Bound State Theory in QED and QCD: Muonium and Pentaquarks

基本粒子的束缚态在自然界中无处不在，是物理学中最有趣和最具挑战性的研究对象之一。对量子电动力学和量子色动力学中束缚态性质的理论研究是本项目的主要目标。介子是一种电子和正介子的松散束缚态，对介子的性质进行研究将减少介子超细分裂的理论不确定性。与日本正在进行的博物馆实验的结果一起，这将导致更精确的电子-介子质量比的值，将允许第一次检测弱相互作用对原子能级能量转移的贡献，并将用于未来的基本物理常数的CODATA调整。隐藏魅力五夸克是最近在欧洲核子研究中心发现的一类新的强相互作用粒子，研究的目标是探索它们的内部结构。将进一步发展五夸克的二元粒子和分子模型，并获得区分这些模型（量子数和质量）的预测，并与实验数据进行比较。这将导致对强相互作用动力学的理解取得进展。五夸克的研究成果将是跨学科的，并将对粒子物理学领域作出贡献。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，既有惊人的实验进展，也有智力上的挑战。电磁束缚双粒子态理论中的许多理论问题，特别是介子态的理论问题，还需要进一步的研究。本研究的目的是减少μ子在10hz以下超细分裂的理论误差（由于尚未计算的贡献）。为了实现这一目标，将计算精细结构常数中大量的七阶后坐力修正和精细结构常数中大量的八阶非后坐力修正。在五夸克理论的工作中，我们将计算氢偶氮原子和分子Pc（4312）的部分衰变宽度，探索两种情况下Pc（4380）宽共振的解释，以及LHCb Pc（4440）和Pc（4457）五夸克在分子图像中的自然解释。与分子Pc（4312）五夸克有关，该小组将寻找一种自然的定性和定量解释，解释比介子重的介子交换如何产生松束缚共振。该奖项反映了美国国家科学基金会的法定使命，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.