Effective Field Theory for Few-Nucleons and Halo Nuclei

核物理研究的一个中心目标是从量子色动力学(QCD)的基本理论来理解核相互作用和性质。然而，在低能时，QCD变得非线性和强相互作用，避开了第一原理纸笔计算原子核的性质。低能核物理的一个重要方面是与弱束缚系统相关的物理。这种系统的一些性质在原子、核物理和粒子物理学中是普遍共享的。有效场论(EFT)公式允许对深深植根于QCD的核性质进行系统计算。EFT允许在用现象学方法难以估计的计算中进行可靠的误差估计。在支持的研究工作中，将构建包含电磁辐射的少体系统的电子理论。将研究与大爆炸核合成和恒星燃烧相关的涉及轻核的关键反应。其中一些反应在解释实验结果方面发挥了重要作用，这些实验结果探索了超越粒子物理标准模型的物理。这项拟议的工作还将引入具有可靠误差估计的新的独立于模型的工具来研究晕核。这些原子核被描述为一个紧密结合的核心，通常有一个或两个价中子形成一个晕圈。这项研究与美国计划在稀有同位素束实验上的重大投资相联系。该研究的更广泛影响包括培训物理学研究生从事数值和分析工作，以便在学术或行业职业生涯中造福社会。这项研究工作的结果将纳入研究生课程。由于上述的普遍性，原子物理学的研究也将受到弱束缚少体系统研究的影响。原子系统具有大的散射长度，是理论和实验研究的一个活跃领域。

A central goal in nuclear physics research is to understand nuclear interactions and properties from the underlying theory of Quantum Chromodynamics (QCD). At low energies, however, QCD becomes non-linear and strongly interacting, eluding first-principle pencil-and-paper calculations of nuclear properties. An important aspect of nuclear physics at low energy is the physics associated with weakly bound systems. Some properties of such systems are universally shared across atomic, nuclear and particle physics. The effective field theory (EFT) formulation allows for systematic calculations of nuclear properties that are deeply rooted in QCD. EFT allows reliable error estimates in calculations that are otherwise difficult to estimate in phenomenological approaches. In the supported research work, EFT for few-body systems involving electromagnetic radiation would be constructed. Key reactions involving light nuclei that are relevant in Big Bang Nucleosynthesis and stellar burning would be studied. Some of these reactions play an important role in interpreting experimental results probing physics beyond the Standard Model of particle physics. The proposed work would also introduce new model-independent tools with reliable error estimates to study halo nuclei. These nuclei are described as a tightly bound core with usually one or two valence neutrons forming a halo. This research ties in with planned major U.S. investment in rare isotope beam experiments.Broader impacts of the research include training of physics graduate students in numerical and analytical work for an academic or industry career benefiting society. Results from this research work would be incorporated in a graduate course. Atomic physics research would also be affected by this study of weakly bound few-body systems due to the universality described above. Atomic systems with large scattering lengths form an active field of theoretical and experimental research.