First-Principle Nuclear Structure and Reactions for Astrophysics and Experiments with Rare Isotope Beams

天体物理学和稀有同位素束实验的第一原理核结构和反应

• 批准号: 2209060
• 负责人: Kristina Launey
• 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: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2209060&HistoricalAwards=false
• 关键词: First; Principle; Nuclear; Structure; Reactions

Following the history-making discovery of nuclear fission, which manifested the huge amount of energy that is released by breaking the strong bonds between neutrons and protons, nuclear physicists have searched for ever more comprehensive explanations of the properties of the atomic nucleus. Such advances are critical to predict exotic nuclei in processes under extreme conditions as stellar mergers and explosions, and to probe neutrino-related processes. The recent advent of radioactive beam facilities has enabled exotic-nuclei measurements, based on collisions of nuclei and their reactions. To predict inaccessible nuclei, these reactions must be well understood and modeled. However, exact solutions exist up to about five particles. The objective of this program is to expand dramatically the capabilities of nuclear reaction theory, by providing input to reaction simulations that is anchored in first principles but also can accommodate heavier nuclei and enhanced deformation. This is important for studies of the origin of elements, one of the biggest challenges in physics today, and has a wider impact since nuclear energy applications and national security research have similar needs. Future leaders (postdoc and students) are trained in low-energy nuclear science and petascale computing, while advancing a web-database for research and educational purposes.The overarching goal is to learn from and inform experiments at radioactive beam facilities, and to predict properties of experimentally inaccessible nuclei that are key to advancing our knowledge about astrophysical processes. The program focuses on improving reaction modeling by constructing the effective interaction between a target and a projectile from first principles (historically, referred to as an optical potential and fitted to experimental data), which now account for the challenging microscopic structure of the participating nuclei. As these interactions are an essential input to numerous reaction models that are currently in use, the new developments serve as an important tool in a broad spectrum of studies. The project capitalizes on a symmetry-guided approach that, by exploiting symmetries known to dominate the dynamics, has enabled ab initio investigations of heavier nuclear species, deformed or not. In this approach, all participating particles are treated on the same footing within a "shell model" picture, while employing chiral effective field theory interactions between protons and neutrons. The end products include calculations of beta decays in nuclei of enhanced deformation, and of reaction observables, e.g., cross sections for scattering, charge-exchange, and (d,p) reactions, of importance to astrophysics.This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments.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.

在核裂变的历史发现之后，核裂变表现出了通过打破中子和质子之间的强键来释放的大量能量，核物理学家已经搜索了对原子核性质的更全面的解释。这种进步对于在极端条件下的过程中预测外在核，如出色的合并和爆炸以及探测与中微子相关的过程。放射性束设施的最近出现，基于核的碰撞及其反应，实现了异国情调的核核测量。为了预测无法访问的核，必须对这些反应进行充分的理解和建模。但是，存在确切的溶液，最高可达五个颗粒。该程序的目的是通过向固定在第一原理中的反应模拟的输入来大大扩展核反应理论的能力，但也可以容纳较重的核并增强变形。这对于研究元素起源的研究很重要，这是当今物理学的最大挑战之一，并且具有更大的影响，因为核能应用和国家安全研究有类似的需求。未来的领导者（博士后和学生）接受了低能量核科学和佩斯卡尔计算的培训，同时推进了用于研究和教育目的的网络数据库。总体目标是在放射性光束设施上学习和告知实验，并预测实验性不可接受的核心属性的属性，以促进我们对人类学的知识的介绍。该计划的重点是通过构建目标与弹丸之间的有效相互作用来改善反应模型（从历史上，被称为光电位并适合实验数据），这现在是参与核的具有挑战性的显微镜结构。由于这些相互作用是当前正在使用的众多反应模型的重要输入，因此新的发展是广泛研究中的重要工具。该项目利用一种对称引导的方法，该方法通过利用已知的主导动态的对称性，从而使较重的核物种的起初研究能够变形与否。在这种方法中，所有参与的粒子都在“壳模型”图片中的相同基础上进行处理，同时采用了质子和中子之间的手性有效田间理论相互作用。最终产品包括计算β衰变的计算，变形增强的核和反应可观察物，例如，散射，电荷交换和（d，p）反应，对天体物理学的重要性，对宇宙中的重要性。这项项目促进了宇宙上的“窗口：跨国公司”的奖励时代。法定任务，并被认为是值得通过基金会的智力优点和更广泛影响的审查标准来评估的值得支持的。

项目成果

Ab initio symmetry-adapted emulator for studying emergent collectivity and clustering in nuclei

• DOI: 10.3389/fphy.2023.1064601
• 发表时间: 2023-03
• 作者: K. S. Becker;K. Launey;A. Ekstrom;T. Dytrych

Emergent symmetries in atomic nuclei: Probing nuclear dynamics and physics beyond the standard model

原子核中的涌现对称性：超越标准模型探索核动力学和物理学

• DOI: 10.21468/scipostphysproc.14.007
• 发表时间: 2023
• 期刊: SciPost Physics Proceedings
• 作者: Launey, Kristina D.;Becker, K. S.;Sargsyan, G. H.;Molchanov, O. M.;Burrows, M.;Mercenne, A.;Dytrych, T.;Langr, D.;Draayer, J. P.
• 通讯作者: Draayer, J. P.

Ab initio single-neutron spectroscopic overlaps in lithium isotopes

• DOI: 10.1103/physrevc.108.054303
• 发表时间: 2022-10
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: G. Sargsyan;K. Launey;R. Shaffer;S. Marley;N. Dudeck;A. Mercenne;T. Dytrych;J. Draayer