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。该项目在一定程度上开启了精确计算核结构和反应的新时代。 活动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，开发和测试一种新的系统方法，以更重的核，并改善从实验中提取信息，最大限度地依赖于模型假设。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：有效场论（EFT）不确定性量化的贝叶斯统计方法，有限密度核系统的EFT，以及过程无关量的计算/提取。贝叶斯方法将被应用到核子间的相互作用，少和多体系统，和电弱探针。他们将解决EFT截断误差，参数估计，模型选择和模型混合。最近的研究的密度矩阵扩展和相空间的贡献，多体计算将是进一步的工作的基础上，有限密度功率计数和EFT核密度泛函理论的重新研究。最后，PI和他的合作者将从重整化群的角度来理解敲除反应的最新进展，这突出了这些相互作用中的尺度和方案依赖性，并提出了如何最好地分析依赖于因子分解假设的实验的问题。应用范围从光学势到短程相关物理的替代治疗。这些项目都有助于微观的目标，模型独立的计算与量化的不确定性的核。他们将影响低能核物理的前沿问题，如长期计划中所概述的，如远离稳定的核物理的结构和反应，这与天体物理学和未来的稀有同位素束设施（FRIB）有关。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智力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. This project enables in part a new era of precision calculations of nuclear structure and reactions. Activities include extending the range and capabilities of statistical methods for assessing theoretical uncertainties and for physics discovery, developing and testing a novel systematic approach to heavier nuclei, and improving the extraction of information from experiment that minimally depends on model assumptions. 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 in three major categories: Bayesian statistical methods for effective field theory (EFT) uncertainty quantification, EFT for finite density nuclear systems, and calculation/extraction of process-independent quantities. The Bayesian methods will be applied to inter-nucleon interactions, few- and many-body systems, and electroweak probes. They will address EFT truncation errors, parameter estimation, model selection, and model mixing. Recent studies of the density matrix expansion and phase-space contributions to many-body calculations will be the basis for further work on finite-density power counting and a renewed study of EFT for nuclear density functional theory. Finally, The PI and his collaborators will build on recent progress in understanding knock-out reactions from a renormalization group perspective, which highlights scale and scheme dependence in these interactions and raises questions about how to best analyze experiments that rely on factorization assumptions. Applications range from optical potentials to alternative treatments of short-range-correlation physics. These projects all contribute to the goal of microscopic, model-independent calculations of nuclei with quantified uncertainties. They will impact forefront problems in low-energy nuclear physics as outlined in the Long Range Plan, such as structure and reactions for the physics of nuclei far from stability, which is relevant for astrophysics and to the future Facility for Rare Isotope Beams (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.