Structure of nuclei far from stability

原子核结构远不稳定

• 批准号: SAPIN-2015-00049
• 负责人: Starosta, Krzysztof
• 金额: $ 7.36万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=617791
• 关键词: Structure; nuclei; far; stability

Low-energy nuclear physics is on the verge of a significant paradigm shift in the basic understanding of its objects of study. In light nuclei it is now possible to provide ab-initio predictions of nuclear structure inspired by the Quantum Chromodynamics (QCD) theory of strong interactions, breaking a decades-long reign of phenomenological effective interactions derived from global or local fits to experimental data. These methods are used for analysis of light-ion induced reactions taking into account their structure within a unified framework; this defies the traditional separation between nuclear reaction and nuclear structure theories. At TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, sustained development in accelerators and sophisticated gamma-ray detection systems permits the study of nuclei very far from stability that tests understanding developed for stable and near-stable nuclei. A striking example is the change of nuclear shell ordering prompted by the neutron or proton excess that rearranges shell structure, often in unexpected ways, and breaks trends of observables such as spins/parities, masses, binding, and excitation energies established near stability. Configuration Interaction methods using two- and three-body interactions inspired by QCD allow the many-body nuclear problem to be solved for medium mass nuclei, including those far from stability, while density functional theories provide a further extension for investigating the validity of these interactions up to the heaviest nuclei. Current theoretical methods track errors imposed by approximations systematically, predicting trends together with uncertainties.

低能核物理对其研究对象的基本理解正处于重大范式转变的边缘。在轻核中，现在可以在强相互作用的量子色动力学（QCD）理论的启发下提供核结构的从头开始预测，打破了长达数十年的从全局或局部拟合实验数据得出的现象学有效相互作用的统治。这些方法用于分析轻离子诱导反应，并在统一框架内考虑其结构；这违背了核反应和核结构理论之间的传统分离。在加拿大粒子与核物理国家实验室 TRIUMF，加速器和先进的伽马射线探测系统的持续发展使得能够研究远离稳定的核，从而测试对稳定和近稳定核的理解。一个引人注目的例子是中子或质子过量引起的核壳层有序性的变化，它通常以意想不到的方式重新排列壳层结构，并打破了可观测量的趋势，例如在稳定附近建立的自旋/宇称、质量、结合和激发能。受 QCD 启发，使用二体和三体相互作用的构型相互作用方法可以解决中等质量原子核的多体核问题，包括那些远离稳定性的原子核，而密度泛函理论则为研究这些相互作用的有效性提供了进一步的扩展，直至最重的原子核。当前的理论方法系统地跟踪近似值带来的误差，预测趋势和不确定性。