Research in Low-Energy Nuclear Theory

强相互作用是质子和中子结合成原子核的原因。 改进对这种情况如何发生的定量理解不仅对美国实验设施的基础核研究至关重要，而且对天体物理学的进步，中微子性质的实验以及能源和国土安全的应用也至关重要。精确计算核结构和反应的时代正在进行中，部分原因是过去NSF赠款PI的研究成果和产品。新的活动将包括扩大评估理论不确定性和物理发现的统计方法的范围和能力，改进从最低限度地依赖于模型假设的实验中提取信息的方法，以及开发和测试一种系统地描述整个核景观的新方法。本科生，研究生和博士后研究人员在开展这些活动中接受的培训直接有助于建设多元化的科学劳动力。学生和博士后必须采用的分析和数值计算的混合是学术和工业研究的良好准备，这是由该集团过去成员的良好记录所证实的。项目分为三大类：贝叶斯统计的有效场理论（EFT）的不确定性量化，计算/提取过程无关的数量，和EFT有限密度核系统。贝叶斯方法将启用本征向量延拓仿真器的扩展，并应用于核子间相互作用，少体和多体系统，和电弱探针。最近的进展的密度矩阵展开和相空间功率计数的多体计算将扩展和EFT核密度泛函理论的新的攻击。最后，该小组将从重整化群的角度扩展最近对敲除反应的计算，该方法利用了这些反应中的尺度和方案依赖性。应用范围从JLab实验相关的短程相关（SRC）物理学的进一步处理和FRIB和天体物理学的敲除和其他反应的新治疗，包括涉及重核反应的光学势的一致使用。这些项目都有助于原子核的微观，模型无关的计算的目标。所有这些项目都将影响核科学长期计划中所概述的低能核物理的前沿问题，例如与多信使天体物理学和FRIB相关的远离稳定的核物理。该奖项反映了NSF的法定使命，并被认为值得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来支持。

The strong interaction is responsible for the binding of protons and neutrons into atomic nuclei. Improved quantitative understanding of how this happens is essential not only for fundamental nuclear research at US experimental facilities but for progress in astrophysics, for experiments on the nature of neutrinos, and for applications to energy and homeland security. The era of precision calculations of nuclear structure and reactions is underway, enabled in part by research findings and products from past NSF grants to the PI. New activities will include extending the range and capabilities of statistical methods for assessing theoretical uncertainties and for physics discovery, improving the extraction of information from experiment that minimally depends on model assumptions, and developing and testing a novel approach to systematically describing the full nuclear landscape. The training received by undergraduates, graduate students, and postdoctoral research associates in carrying out these activities contributes directly to the building of a diverse scientific workforce. The mix of analytical and numerical computation the students and postdocs must employ is excellent preparation for both academic and industrial research, which is validated by the strong track record of past members of the group. Projects are proposed in three major categories: Bayesian statistics for effective field theory (EFT) uncertainty quantification, calculation/extraction of process-independent quantities, and EFT for finite density nuclear systems. The Bayesian methods will be enabled by the extension of eigenvector continuation emulators and applied to inter-nucleon interactions, few- and many-body systems, and electroweak probes. Recent progress on the density matrix expansion and phase-space power counting for many-body calculations will be extended and a renewed attack on EFT for nuclear density functional theory will be made. Finally, the group will extend recent calculations of knock-out reactions from a renormalization group perspective, which exploits scale and scheme dependence in these reactions. Applications range from further treatments of short-range-correlation (SRC) physics relevant for JLab experiments and novel treatments of knock-out and other reactions for FRIB and astrophysics, including the consistent use of optical potentials for reactions involving heavy nuclei. These projects all contribute to the goal of microscopic, model-independent calculations of nuclei. All of these projects will impact forefront problems in low-energy nuclear physics as outlined in the Long Range Plan for Nuclear Science, such as the physics of nuclei far from stability, which is relevant for multi-messenger astrophysics and to FRIB.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.