Theoretical Study of M1 and Gamow-Teller Transitions in Nuclei

原子核中 M1 和伽莫夫-泰勒跃迁的理论研究

• 批准号: 08640390
• 负责人: SUZUKI Toshio
• 金额: $ 1.41万
• 依托单位: Nihon University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640390/
• 关键词: neutron halo; Gamow-Teller; spin-dipole; isobaric analog state; beta decay; sum rule; spreading width; muon capture; E1巨大共鳴; ソフトGDR; ピグミー共鳴; スピン双極子状態; 超微細構造; ガモフ・テラー状態; 多粒子-多空孔; 中性孔ハロ-; 磁気モーメント; ハイパー核; 中性子ハロ-

1. Effects of halo on the retardation of the Gamow - Teller (GT) beta transition from ^<11>Li as well as on the Coulomb displacement energy of the isobaric analog state (lAS) of ^<11>Li are investigated. The structure of the two-neutron halo state in ^<11>Li is determined.2. Spreading and quenching of the GT strength in ^<90>Zr and ^<208>Pb are found to be mainly caused by the coupling to the 2p - 2h configurations. Observed GT strengths are well reproduced by our calculations.3. Sum rule for the Ml transitions between GT and lAS is derived, which is found to be extremely enhanced compared to the sum rule for the parent nucleus. The effects in ^<11>Li, in particular, are investigated.4. Spreading effects due to the tensor interaction in spin-dipole transition strengths are investigated. Sum rules for the E1 transitions between the GT and spin-dipole states are derived for various configuration spaces.5. Relation between the spreading width of the IAS and the isospin mixing in the parent state is obtained. New formula for the isospin dependence of the spreading width is derived and applied to the recent observations, which prove to be quite successful.6. Importance of the effects of the halo in "Be is pointed out for the muon capture rate in ^<11>B as well as for the hyperfine anomaly in Be isotopes.7. Effects of K and PI meson exchange currents on magnetic moments of hypernuclei are studied. Structure of pigmy E1 resonances in neutron-rich nuclei, ^<18*24>O, soft-GDR in ^<11>Li and GDR on the soft-GDR are investigated.

1. 研究了光晕对^< 11b>li的Gamow - Teller (GT) β跃迁延迟的影响以及对^< 11b>li的等压模拟态（lAS）的库仑位移能的影响。确定了^<11>Li中双中子晕态的结构。^<90>Zr和^<208>Pb中GT强度的扩散和淬火主要是由于与2p - 2h结构的耦合引起的。我们的计算很好地再现了观测到的GT强度。导出了GT和lAS之间的Ml跃迁的和规则，与母核的和规则相比，该规则得到了极大的增强。我们特别研究了^< 11bb10li的效应。研究了自旋偶极子跃迁强度中张量相互作用的扩散效应。推导了不同构型空间中GT态和自旋偶极子态之间E1跃迁的和规则。得到了IAS的扩散宽度与母态同位旋混合的关系。推导了同位旋与扩散宽度的关系的新公式，并将其应用于最近的观测，证明是相当成功的。指出了Be的晕效应对^< 11b>b的介子俘获率和Be同位素的超精细异常的重要性。研究了K介子交换电流和PI介子交换电流对超核磁矩的影响。研究了富中子核^<18*24> 0、^<11 >li中的软GDR和软GDR上的GDR的结构。

项目成果

T.Suzuki: "Effects of neutron halo on Gamow-Teller β decay and muon capture" Proceedings of the International Workshop on Physics of Unstable Nuclear Beams, Sao Paulo, (World Scientific). 157-164 (1997)

T.Suzuki：“中子晕对 Gamow-Teller β 衰变和 μ 子捕获的影响”，不稳定核束物理国际研讨会论文集，圣保罗，（世界科学）157-164（1997 年）。

T.Suzuki: "Electric dipole transitions between Gamow-Teller and spin-dipole states" Physical Review. C57. 139-144 (1998)

T.Suzuki：“伽莫夫泰勒态和自旋偶极态之间的电偶极子跃迁”物理评论。

H.Sagawa, Nguyen Van Giai and T.Suzuki: "Isospin mixing and super-allowed Fermi beta decay" Physical Review. C53. 2163-2170 (1996)

H.Sakawa、Nguyen Van Giai 和 T.Suzuki：“同位旋混合和超级允许的费米 beta 衰变”物理评论。

T.Suzuki: "Distribution of Gamow-Teller strength in ^<11>Li" Proceedings of the International Symposium on Non-Nucleonic Degrees of Freedom Detected in Nucleus, (World Scientific). (1997)

T.Suzuki：“^<11>Li 中伽莫夫泰勒强度的分布”，原子核中检测到的非核自由度国际研讨会论文集，（世界科学出版社）。

T.Suzuki: "Possible enhancement of magnetio dipole transition strengths between Gamow-Teller and isobaric analog states" Nuclear Physics. A599. 153-158 (1996)

T.Suzuki：“伽莫夫泰勒和等量异位模拟态之间磁偶极子跃迁强度的可能增强”核物理。