Study of single particle and collective states in nuclei near drip lines

滴水线附近原子核中的单粒子和集体态研究

• 批准号: 09640369
• 负责人: SAGAWA Hiroyuki
• 金额: $ 1.73万
• 依托单位: UNIVERSITY OF AIZU
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640369/
• 关键词: Drip Line Nuclei; Giant Resonances; Effectine Charges; Gamow Teller State; Isobaric Gnalogue States; ハロー原子核; スキン原子核; ピグミー共鳴; 相対論的平均場近似; スピン軌道力; ガモフ、テラー状態

In this project, the following terms have been studied intensively :1) proton-neutron RPA response function and excited states in skin nuclei.The existence of thick skin has been observed in He-isotopes and A=20 isobars. In these nuclei, one-body field is very different from those of stable nuclei. For example, the radial dependence of the one-body potential is different from that of Woods-Saxon potential and rather close to harmonic oscillator one. In this study, the response of drip line nuclei ^<24>O, ^<48>Ni and ^<60>Ca have been studied especially focusing on the threshold strength.2) Pigmy resonances and Giant resonances in drip line nuclei We have studied dipole states of oxygen-isotopes in large scale shell model calculations. The calculated photoreaction cross sections in ^<16>O and ^<18>O give reasonable agreement with experimental observations both in the low energy region below hω=15 MeV and in the high energy giant resonance region (15 MeV<hω【less than or equal】30 MeV).3) Isospin violation and restoration in thermal compound systemsExplicit relations between the isospin mixing probability, the spreading width Γ^↓_<IAS> of the Isobaric Analog State (IAS) and the statistical decay width Γ_c of the compound nucleus at finite excitation energy, are derived by using the Feshbach projection.

本课题重点研究了以下几个方面：1)质子-中子RPA响应函数和皮肤核的激发态。在氦同位素和A=20等压线中观察到厚皮的存在。在这些原子核中，单体场与稳定原子核的单体场有很大的不同。例如，单体势的径向依赖性与伍兹-撒克逊势不同，而与谐振子势相当接近。本研究研究了滴线核^<24>O, ^<48>Ni和^<60>Ca的响应，特别关注阈值强度。在大尺度壳模型计算中研究了氧同位素的偶极态。计算得到的^<16>O和^<18>O的光反应截面与实验观测结果在hω=15 MeV以下的低能区和高能巨共振区（15 MeV<hω【小于或等于】30 MeV）均有较好的一致性。3)热化合物体系的同位旋破坏与恢复利用Feshbach投影，推导了在有限激发能下，化合物核的同位旋混合概率、等压模拟态（IAS）的扩散宽度Γ^↓_<IAS>与统计衰变宽度Γ_c之间的隐式关系。

项目成果

H.Kitugawa: "Reaction Cross Sections and Radii of A=17 and A=20 isomers"Zeitschrift fur Physik. A358. 381-387 (1997)

H.Kitukawa：“A=17 和 A=20 异构体的反应截面和半径”Zeitschrift Fur Physik。

I.Hamamoto: "Structure of Giant Quadrupole Reserances in Neutron Drip Line Nuclei"Physical Review. C55. 2361-2368 (1997)

I.Hamamoto：“中子滴线核中巨型四极储备的结构”物理评论。

T.Minamizono: "Electromagnefic Moments of β- emltling Nucleus ^<19>O"Physical Letters. B457. 9-16 (1999)

T.Minamizono：“β-核磁矩 ^<19>O”《物理快报》B457（1999）。

I.Hamamoto, H.Sagawa and X.Z.Zhang: "Structure of Giant Quadrupole Resonances in Neutron Drip Line Nuclei"Phys.Rev.. C55. 2361-2368 (1997)

I.Hamamoto、H.Sakawa 和 X.Z.Zhang：“中子滴线核中巨型四极共振的结构”Phys.Rev.. C55。

I.Hamamoto and H.Sagawa: "Response of light drip line nuclei to spin dependent operators"Phys.Rev.. C60. 064314-1-064314-7 (1999)

I.Hamamoto 和 H.Sakawa：“光滴线核对自旋相关算子的响应”Phys.Rev.. C60。