Theoretical Research of Sof-dipole Resonances in Light Neutron-Rich Nuclei

轻富中子核中软偶极子共振的理论研究

• 批准号: 12640246
• 负责人: KATO Kiyoshi
• 金额: $ 1.66万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640246/
• 关键词: NEUTRON-RICH NUCLEI; COMPLEX SCALING METHID; JOST FUNCTION METHOD; COULOMB BREAKUP REACTION; SOFT-DIPOLE RESONANCES; 中性子ハロー; 拡張された3体模型; 対相関; ソフト・ダイポール; 不安定核; 仮想状態; ヨスト関数法

The purpose of this project is to obtain a theoretical conclusion about existence and observation of soft-dipole resonaces in ^6He and ^<11>Li whichare typical nuclei of light neutron rich nuclei. For this purpose, the following three problems were studied in these three years of 2000-2002 and desired results were successfully obtained :(1) Theoretical researches of soft-dipole resonances in three-body Coulomb breakup reactions. Using the complex scaling method, we developed a new theoretical framework to treat three-body breakup reactions. Applying this new method to ^6He and 11Li, we calculated the breakup cross sections where contributions from soft-dipole resonances are negligible.(2) Study of binding and excitation mechanisms by using an extended core+n+n model where internal degrees of freedom of the core cluster are taken into account. It was shown that the pairing correlations not only between valence neutrons but also between neutrons in the ^9Li core play an important role in the binding mechanism and a large amplitude of s-wave components.(3) Mechanism of appearance of s-wave anti-bound states. Analyses of s-wave anti-bound states in ^4He-n and ^9Li-n systems gave a clear relation between position of anti-bound poles and property of ^4He-n and ^9Li-npotentials.

本项目的目的是获得轻丰中子核的典型核^6He和^6Li中软偶极共振的存在和观测的理论结论<11>。为此，在2000-2002年的三年中，我们对以下三个问题进行了研究，并取得了预期的结果：（1）三体库仑破裂反应中软偶极共振的理论研究。利用复标度法，我们发展了一个新的理论框架来处理三体分裂反应。将这种新方法应用于^6 He和11 Li，我们计算了软偶极共振贡献可以忽略的碎裂截面。(2)利用扩展的核心+n+n模型研究了结合和激发机制，该模型考虑了核心团簇的内部自由度。结果表明，不仅价中子之间的配对关联，而且^9Li核中中子之间的配对关联在束缚机制和s波分量的大幅值中起着重要作用。(3)s波反束缚态出现的机制。对^4 He-n和^9 Li-n系统s波反束缚态的分析给出了反束缚极的位置与^4 He-n和^9 Li-n势性质之间的明确关系。

项目成果

M.Ito: "^6He+^6He Molecular Resonances of Highly-Excited States"RIKEN review. 39. 123-128 (2001)

M.Ito：“^6He ^6He 高激发态分子共振”RIKEN 评论。

G.F.Filippov: "Fock-Bargmann Space and Classical Trajectories"Phys. Part. Nucl.. 32. 405-426 (2001)

G.F.Filippov：“福克-巴格曼空间和经典轨迹”物理学。

K.Kato: "Beyond the Core+n+n Model Based on the Complex Scaling Method"Prog. Theor. Phys. Supp.. 146. 179-189 (2002)

K.Kato：“超越基于复杂尺度方法的核心 n n 模型”Prog。

H.Masui: "Coupled-channel Study for O-isotopes with the Core plus Valence Neutrons Model"AIP Conference Proceedings. 644. 74-79 (2002)

H.Masui：“用核心加价中子模型进行 O 同位素的耦合通道研究”AIP 会议记录。

Nozomi Yabusaki: "Masses and OZI-Allowed Decay Widths of Upsilon-States in a Coupled Channel Model"Prog. Theor. Phys.. 106. 389-400 (2001)

Nozomi Yabusaki：“耦合通道模型中 Upsilon 态的质量和 OZI 允许的衰变宽度”Prog。