Clarification of neutron-proton pairing correlation and condensation

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K17680
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: University of Tsukuba
• Principal Investigator: Hinohara Nobuo 筑波大学, 計算科学研究センター, 助教 (80511435)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 原子核密度汎関数法 / 対相関

Outline of Final Research Achievements

Atomic nuclei are composed of neutrons and protons, and their low-energy states are strongly affected by the two-nucleon pair correlations. In this research we showed the possibility of determination of the pairing coupling constants using the pairing rotational moment of inertia that was proposed as a new experimental indicator of the nuclear pairing condensation. We also implemented the neutron-proton pairing in the nuclear density functional theory solver and analyzed the neutron-proton pair condensed phase in proton-rich unstable nuclei.
We showed the importance of the isospin symmetry in the pairing channel in a realistic system with the isospin symmetry broken by the Coulomb interaction.

Free Research Field

原子核理論

Academic Significance and Societal Importance of the Research Achievements

中性子－陽子対凝縮相が陽子過剰不安定核の基底状態で発現するかどうかは原子核構造理論の重要な未解決問題である。さらにこれらの原子核は元素合成過程であるｒｐプロセスの経路上に位置するため、重元素生成の理解にもつながる。本研究で行った対回転の慣性モーメントによる対相関の詳細の決定、さらに世界に先駆けて開発した中性子－陽子対相関を含む原子核密度汎関数法の計算コードは、中性子－陽子対凝縮相の完全な理解に向けた重要な成果であると位置づけられる。