Nuclear Structure and Reactions from Lattice Effective Field Theory

量子色动力学（QCD）是强相互作用的理论，强相互作用是自然界中的基本力，它通过形成原子核的质子和中子之间的相互作用来表现自己。 量子色动力学的理论研究是核物理工作的核心，这些工作寻求更好地理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，用于计算与时间相关的量，特别是核反应速率，这对于开发原子核如何相互作用以产生出现在周期表中的基本元素的天体物理模型非常重要。 了解这些速率可以深入了解早期宇宙的物理学以及在恒星中产生能量的核反应。该项目的更广泛的影响包括培养研究生从事数值和分析工作，以造福社会的学术或工业事业。该项目建立在研究人员之前使用美国国家科学基金会资助的资金介绍的格点EFT绝热投影方法的基础上。 典型的低能反应涉及两个原子核之间的相互作用。绝热投影方法允许从原子核本身的微观描述开始，以几个质子和中子的形式，对参与的原子核进行有效的两体描述。这些想法在这里以几种方式得到进一步发展。混合通道反应计算是重要的非弹性过程中描述。涉及电磁辐射的反应将被计算出来。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有关的涉及轻核的关键反应。其中一些反应在解释粒子物理学标准模型之外的实验结果方面发挥着重要作用。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晕。这项研究与美国计划对稀有同位素束实验的重大投资有关。

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.