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。提高对这一过程的定量理解，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、对中微子性质的实验以及对能源和国土安全的应用都至关重要。精确计算核结构和核反应的时代正在到来，这在一定程度上是由过去NSF资助PI的研究成果和产品实现的。新的活动将包括扩大用于评估理论不确定性和物理发现的统计方法的范围和能力，改进从最小程度依赖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员在开展这些活动时所接受的培训，直接有助于建设一支多样化的科学队伍。学生和博士后必须使用的分析和数值计算的组合为学术和工业研究做了极好的准备，这被该小组过去成员的良好记录所证实。项目主要分为三大类：有效场论（EFT）不确定性量化的贝叶斯统计，过程无关量的计算/提取，有限密度核系统的EFT。贝叶斯方法将通过特征向量延拓仿真器的扩展得以实现，并应用于核子间相互作用、少体和多体系统以及电弱探针。本文将对多体计算中密度矩阵展开和相空间功率计数的最新进展进行扩展，并对核密度泛函理论中的EFT进行重新研究。最后，该小组将从重整化基团的角度扩展最近的敲除反应计算，利用这些反应的规模和方案依赖性。应用范围从与JLab实验相关的短程相关（SRC）物理的进一步处理，到FRIB和天体物理学的敲除和其他反应的新处理，包括在涉及重核的反应中持续使用光势。这些项目都有助于实现核的微观、独立于模型的计算目标。所有这些项目都将影响《核科学长期计划》中概述的低能核物理领域的前沿问题，例如与多信使天体物理学和FRIB相关的远离稳定的原子核物理学。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。

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.