RII Track-4:NSF: Exploring the Emergent Features of Exotic Nuclear Systems with First-principles Theory of Nuclear Reactions

RII Track-4：NSF：利用核反应第一原理理论探索奇异核系统的新兴特征

• 批准号: 2327385
• 负责人: Alexis Mercenne
• 金额: $ 30万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-11-15 至 2025-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2327385&HistoricalAwards=false
• 关键词: RII; Track; NSF; Exploring; Emergent

This research project aims to investigate the fundamental properties of the atomic nucleus and its role in the cosmos through first-principles calculations of nuclear reactions. Recent advancements in our understanding of the nuclear force have ushered in an era of first-principles studies focusing on atomic nuclei. However, existing approaches utilizing these advancements for the study of nuclear reactions involving elements heavier than the lightest isotopes still rely on approximations, thereby introducing significant uncertainties. To address this void, the project will leverage state-of-the-art mathematical techniques and computational resources from the most advanced supercomputers in the US. By doing so, it aims to achieve unprecedented levels of accuracy in the description of nuclear reactions. This endeavor is expected to yield highly accurate predictions for systems currently beyond the reach of experimental methodologies, thereby potentially catalyzing breakthroughs in both nuclear science and astrophysics. The project will culminate in the development of a novel computational tool capable of investigating various reaction processes within a unified framework. The anticipated outcomes are poised to exert a significant impact not only in the domain of nuclear physics but also across various fields of astrophysical research as well as in the context of national security.Recent advancements in our comprehension of the nuclear force and high-performance computing, have paved the way for the era of first-principles calculations in nuclear physics. These developments have yielded unprecedentedly accurate results for light nuclei. However, such calculations rapidly become computationally infeasible for systems exceeding a dozen particles, even on the most advanced computing platforms. In this context, it has been demonstrated that reformulating the many-body problem in a new basis—capitalizing on nearly perfect symmetries identified earlier in the history of nuclear physics—can mitigate the combinatorial challenges inherent to first-principles calculations. This innovative approach, the Symmetry-adapted No Core Shell Model has enabled the ab initio description of nuclear structures for systems containing up to 40 particles, achieving a high fidelity to experimental data, particularly for electromagnetic transitions traditionally difficult to grasp in ab initio approaches. Building on this success, the current project aims to extend this theoretical framework to encompass nuclear reactions by utilizing the Resonating Group Method (RGM). In collaboration with Lawrence Livermore National Laboratory, the project seeks to expand the reach of ab initio reaction calculations to study nuclei up to the calcium region. Within the RGM framework, the project will allow a coupled-channel description of reaction process involving various mass partitions and light projectiles from first-principles. The anticipated outcomes hold the promise of impactful applications across multiple domains of astrophysics, as well as significant implications for national security.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.

该研究项目旨在通过核反应的第一性原理计算来研究原子核的基本性质及其在宇宙中的作用。我们对核力理解的最新进展开创了以原子为重点的第一性原理研究的时代。然而，利用这些进步来研究涉及比最轻同位素更重的元素的核反应的现有方法仍然依赖于近似值，从而引入了显着的不确定性，为了解决这一空白，该项目将利用这一点。通过使用美国最先进的超级计算机的最先进的数学技术和计算资源，它的目标是在核反应的描述方面达到前所未有的准确性。该项目最终将开发出一种能够在统一框架内研究各种反应过程的新型计算工具，从而可能促进核科学和天体物理学的突破。一个不仅在核物理领域，而且在天体物理研究的各个领域以及国家安全方面都产生了重大影响。我们对核力和高性能计算的理解的最新进展，为这个时代铺平了道路这些发展为轻核提供了前所未有的精确结果，但是，即使在最先进的计算平台上，这种计算在计算上也很快变得不可行。证明了在新的基础上重新表述多体问题——利用核物理历史上早期发现的近乎完美的对称性——可以减轻第一性原理计算固有的组合挑战。这种创新方法，即对称性适应的无核壳模型。能够对包含多达 40 个粒子的系统的核结构进行从头开始描述，实现了实验数据的高保真度，特别是对于传统上从头开始方法难以掌握的电磁跃迁。目前的项目旨在通过利用共振群法（RGM）将这一理论框架扩展到包括核反应，该项目与劳伦斯利弗莫尔国家实验室合作，旨在扩大从头反应计算的范围，以研究原子核。在 RGM 框架内，该项目将允许从第一原理对涉及各种质量分区和轻射弹的反应过程进行耦合通道描述，预期结果有望在天体物理学的多个领域产生影响。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。