Ab initio theory of light and medium mass nuclei

轻质和中等质量核从头算理论

• 批准号: SAPIN-2016-00033
• 负责人: Navratil, Petr
• 金额: $ 5.83万
• 依托单位: TRIUMF
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=660711
• 关键词: Ab; initio; theory; light; medium

Atomic nuclei are quantum many-body systems made by protons and neutrons interacting with forces that originate from the fundamental theory of Quantum Chromo-Dynamics. The exact treatment of nuclei starting from the constituent nucleons and the inter-nucleon interactions among them has been a long-standing goal in nuclear physics. ******The goal of this project is to develop a predictive ab initio theory of nuclear structure and nuclear reactions for light and medium mass nuclei. Such a theory is needed for understanding of exotic nuclei investigated at rare isotope facilities like ISAC at TRIUMF, for understanding of nuclear reactions important for astrophysics, for understanding of fusion reactions important for the future energy generation as well as for the testing of fundamental symmetries in nuclear processes. At the same time, it provides a feedback on the quality of inter-nucleon iteractions used as input to these calculations and ultimately helps to improve our knowledge of the nucleon-nucleon interaction, and in particular of the still-not-completely-understood three-nucleon interaction. ******In this proposal, we combine an ab initio nuclear structure approach capable to describe bound states of light nuclei with a microscopic cluster method developed to describe reactions of nuclear clusters. The resulting method provides a unified description of both bound and unbound nuclear states starting from inter-nucleon interactions among protons and neutrons. We will apply this method to improve our understanding of exotic nuclei such as 9He, 11N, or 17C, to describe halo nuclei like 11Be or 11Li. Using state-of-the-art nuclear forces including the three-nucleon interaction, we will calculate rates of nuclear reactions important for astrophysics including 7Be(p,gamma)8B, 3He(4He,gamma)7Be, 2H(alpha,gamma)6Li and 4He(nn,gamma)6He that are difficult or impossible to measure at low energies at which these reactions occur in cosmic environments. We will also investigate fusion reactions such as 3H(d,n)4He and the aneutronic 11B(p,alpha)8Be relevant for future energy generation. We will study beta decay of 6He that is being measured as an important test of physics beyond the Standard Model. We will also contribute to ab initio investigatinos of medium mass nuclei with one of the major goals to improve calculations of the neutrinoless double-beta decay matrix elements. Finally, a long-term goal of this project is the calculation of reactions important for stellar synthesis of 12C and 16O. It is anticipated that the complexity of theoretical understanding of these reactions equires exa-scale computing.**

原子核是由质子和中子与源自量子色动力学基本理论的力相互作用形成的量子多体系统。从组成核子及其核子间相互作用开始精确处理原子核一直是核物理学的长期目标。 ******该项目的目标是开发轻质和中等质量核的核结构和核反应的从头算预测理论。为了理解在 TRIUMF 的 ISAC 等稀有同位素设施中研究的奇异核、理解对天体物理学重要的核反应、理解对未来能源产生重要的聚变反应以及测试基本对称性，需要这样的理论。核过程。同时，它提供了有关核子间迭代质量的反馈，用作这些计算的输入，并最终有助于提高我们对核子-核子相互作用的了解，特别是对尚未完全理解的三个相互作用的了解。 -核子相互作用。 ******在本提案中，我们将能够描述轻核束缚态的从头算核结构方法与开发用于描述核团簇反应的微观团簇方法相结合。由此产生的方法提供了从质子和中子之间的核子间相互作用开始的束缚和非束缚核态的统一描述。 我们将应用这种方法来提高我们对 9He、11N 或 17C 等奇异核的理解，以描述 11Be 或 11Li 等晕核。利用最先进的核力（包括三核子相互作用），我们将计算对天体物理学重要的核反应速率，包括 7Be(p,gamma)8B、3He(4He,gamma)7Be、2H(alpha,gamma) 6Li 和 4He(nn,gamma)6He 在宇宙环境中发生这些反应的低能量下很难或不可能测量。我们还将研究与未来能源产生相关的聚变反应，例如 3H(d,n)4He 和非中子 11B(p,alpha)8Be。我们将研究 6He 的贝塔衰变，该衰变正在作为标准模型之外的重要物理测试进行测量。我们还将为中等质量核的从头开始研究做出贡献，主要目标之一是改进无中微子双β衰变矩阵元素的计算。最后，该项目的长期目标是计算对 12C 和 16O 恒星合成重要的反应。预计这些反应的理论理解非常复杂，需要亿亿级计算。**