Greens Functions and the Nuclear Many-Body Problem

格林函数和核多体问题

• 批准号: 2207756
• 负责人: Willem Dickhoff
• 金额: $ 30万
• 依托单位: Washington 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: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207756&HistoricalAwards=false
• 关键词: Greens; Functions; Nuclear; Many; Body

The properties of nuclei with extreme neutron to proton ratios are becoming available for experimental scrutiny at facilities like the Facility for Rare Isotope Beams (FRIB) starting shortly on the campus of Michigan State University. Most of the experimental probes to study these exotic nuclei involve particles that interact strongly themselves making it difficult to extract the properties of individual protons or neutrons in these exotic systems. The project aims at overcoming this difficulty by providing a simultaneous description of positive energy nucleons, the domain of elastic scattering, and bound nucleons, the domain of nuclear structure, using the framework of the propagator method of quantum mechanics. This approach will provide critical insights into the properties of very neutron-rich nuclei, and is therefore relevant for the physics of neutron stars by clarifying where neutrons are found with respect to the distribution of protons and how neutrons are captured by neutron-rich nuclei. The PI will mentor graduate students in this research and collaborate with experimental colleagues who will perform related experiments.The propagator method will be utilized with non-local potentials constrained by experimental data that allow for the accurate description of ground-state properties of nuclei by the method of dispersion relations. Simultaneously, this implementation will be able to describe or predict all relevant experimental data in the continuum including elastic scattering cross sections. It will therefore be possible to study various nuclear reactions using the ingredients of this method in analogy to the successful analysis of electron-induced proton knockout reactions thereby clarifying the properties of protons and neutrons in exotic nuclei as well as suggesting relevant new experiments. In particular reactions involving deuterons will be studied employing potentials that are nonlocal and obey dispersion relations. Continued interest in the prediction of the neutron distribution for nuclei with excess neutrons will be maintained. An extension of the method will be developed to allow a simultaneous description of response functions. The propagator method will also be employed to calculate the properties of nuclei by starting from the underlying interactions between nucleons as constrained by the symmetries of the fundamental theory of quarks and gluons, Quantum Chromo Dynamics and the available data for the properties of two nucleons. Such calculations will be applied with a new strategy that allows the ab initio calculation of scattering properties of heavier nuclei that have not been studied in this way to date.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.

具有极端中子与质子比的原子核的特性即将在密歇根州立大学校园内的稀有同位素束设施 (FRIB) 等设施中进行实验审查。大多数研究这些奇异核的实验探针都涉及自身相互作用强烈的粒子，因此很难提取这些奇异系统中单个质子或中子的特性。该项目旨在通过使用量子力学传播器方法的框架，同时描述正能量核子（弹性散射域）和束缚核子（核结构域）来克服这一困难。这种方法将为了解非常富含中子的原子核的性质提供重要的见解，因此通过阐明中子在质子分布方面的位置以及中子如何被富含中子的原子核捕获，从而与中子星物理学相关。 PI 将在这项研究中指导研究生，并与进行相关实验的实验同事合作。传播器方法将与受实验数据约束的非局域势一起使用，从而可以通过色散关系法。同时，该实现将能够描述或预测连续体中的所有相关实验数据，包括弹性散射截面。因此，可以使用该方法的成分来研究各种核反应，类似于电子诱导质子敲除反应的成功分析，从而阐明奇异核中质子和中子的性质，并提出相关的新实验。特别是涉及氘核的反应将利用非局域且服从色散关系的势来研究。人们将继续对预测具有过量中子的原子核的中子分布感兴趣。将开发该方法的扩展以允许同时描述响应函数。传播器方法还将用于从核子之间的潜在相互作用开始计算核的性质，该相互作用受到夸克和胶子基本理论、量子色动力学的对称性以及两个核子性质的可用数据的限制。此类计算将采用一种新策略，该策略允许对迄今为止尚未以这种方式研究过的较重原子核的散射特性进行从头计算。该奖项反映了 NSF 的法定使命，并通过使用基金会的评估进行评估，被认为值得支持。智力价值和更广泛的影响审查标准。

项目成果

Optical potentials for the rare-isotope beam era

稀有同位素束时代的光学潜力

• DOI: 10.1088/1361-6471/acc348
• 发表时间: 2023-04
• 期刊: Journal of Physics G: Nuclear and Particle Physics
• 作者: Hebborn, C.;Nunes, F. M.;Potel, G.;Dickhoff, W. H.;Holt, J. W.;Atkinson, M. C.;Baker, R. B.;Barbieri, C.;Blanchon, G.;Burrows, M.;et al
• 通讯作者: et al