Spin responses of nuclei, nuclear weak transition processes and nucleosynthesis

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K05090
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nihon University
• Principal Investigator: SUZUKI Toshio 日本大学, 文理学部, 教授 (70139070)
• Research Collaborator: HONMA michio
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: スピン応答 / 殻模型 / 電子捕獲 / β崩壊 / ニュートリノ-原子核反応 / 元素合成 / 核ＵＲＣＡ過程 / 中性子ハロー

Outline of Final Research Achievements

Accurate evaluations of electron-capture and β-decay rates in stellar environments with high densities and temperatures as well as neutrino-nucleus reaction cross sections have been systematically done for wide ranges of nuclei including fp- and sd-shells based on new shell-model Hamiltonians, which can describe spin responses of nuclei quite well. These weak rates have been applied to study nucleosynthesis of neutron-rich iron-group elements in type Ia supernova exolosions, r-process nucleosynthesis in core-collapse supernovae and binary neutron star mergers, and nuclear URCA processes in O-Ne-Mg cores of stars, which result in important contributions to nucleosynthesis and evolution of stars as well as compilation of nuclear data with high accuracies.
Structute of two-neutron halo in 1n 22C has been clarified based on fundamental nyucleon-nucleon interaction, and discovery of a new magic number Z=6 has been made.

Free Research Field

原子核理論

Academic Significance and Societal Importance of the Research Achievements

原子核分野での基本的核力を基にした中性子過剰核、不安定核の最近の研究成果、構造研究の精密化の成果は、原子核でのスピン応答の精密な記述を可能にしテンソル力等のスピンに依存する核力成分の重要な役割を明らかにしただけでなく、精密なスピン依存型核遷移率を天体での元素合成や星の進化の分野の研究へ応用、反映させることによって、原子核物理、天体物理両分野間の密接な共同研究、両分野間の研究のフィードバックの促進をもたらした。今後、それぞれの分野での研究がさらに発展することが期待される。
分野をまたいだ研究成果は、一般社会での興味と関心を引きやすく、その理解を深めることに貢献すると期待される。