Nuclear Structure and Reactions from Lattice Effective Field Theory

量子色动力学(QCD)是强相互作用理论，这是自然界中的基本力，通过构成原子核的质子和中子的积木之间的相互作用来体现。QCD的理论研究是核物理努力的核心，这些努力寻求更好地了解宇宙中发生的基本过程，这些过程最终影响地球上的生命。在这个项目中，PI将开发新的理论和数值技术来计算依赖于时间的量，特别是对于开发核如何相互作用以产生出现在元素周期表中的基本元素的天体物理模型非常重要的核反应速率。知道这些速率有助于洞察早期宇宙的物理学和产生恒星能量的核反应。这个项目的更广泛的影响包括培训研究生从事学术或行业的数值和分析工作，使社会受益。这个项目建立在格子EFT的绝热投影法的基础上，该方法是由研究人员利用美国国家科学基金会的资金引入的。典型的低能反应涉及两个原子核之间的相互作用。绝热投影法允许从几个质子和中子对原子核本身的微观描述开始，对参与的原子核进行有效的二体描述。在这里，这些想法在几个方面得到了进一步的发展。计算了在描述非弹性过程中很重要的混合通道反应。涉及电磁辐射的反应将被计算出来。我们将研究库仑力引起的原子核之间的长程相互作用。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。这些计算将补充晕核领域的类似工作。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。

Quantum Chromodynamics (QCD) is the theory of strong interactions, the fundamental force in nature that manifests itself by interactions between the building blocks of protons and neutrons that form the nuclei of atoms. Theoretical studies of QCD are central to nuclear physics efforts that seek a better understanding of the fundamental processes taking place in the Universe, processes that ultimately impact life on Earth. In this project, the PI will develop new theoretical and numerical techniques for calculating time-dependent quantities, in particular the nuclear reaction rates important for the development of astrophysical models of how nuclei interact to generate the fundamental elements that appear in the periodic table. Knowing these rates gives insight into the physics of the early universe and the nuclear reactions that produce the energy in stars. Broader impacts of this project include training of graduate students in numerical and analytical work for an academic or industry career benefiting society.This project builds on the adiabatic projection method for lattice EFT that was previously introduced by the investigator using funds from a U.S. National Science Foundation grant. Typical low energy reactions involve interactions between two atomic nuclei. The adiabatic projection method allows an effective two-body description of the participating nuclei starting from a microscopic description of the nuclei themselves in terms of several protons and neutrons. These ideas are developed further, here, in several ways. Mixed channel reactions are calculated that are important in describing inelastic processes. Reactions involving electromagnetic radiation would be calculated. Long-range interaction between nuclei due to the Coulomb force would be studied. 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. These calculations would complement similar efforts in the field of 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.