THEORETICAL STUDY OF NUCLEI WITH STRANGENESS

奇异核的理论研究

• 批准号: 08239104
• 负责人: MOTOBA Toshio
• 金额: $ 15.68万
• 依托单位: OSAKA ELECTRO-COMMUNICATION UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 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/en/grant/KAKENHI-PROJECT-08239104/
• 关键词: Hypernucleus; Hyperon-nucleon interaction; Nonmesonic weak decay; Hypernuclear lifetime; Strangeness halo; Double hypernucleus; H-particle; Quark Model; ハイパー原子核; ダブルハイパー核; ハイパロン核子相互作用; パイ中間子型弱崩壊; ストレンジネス・ハロ-; グザイ・ハイパー核; 非中間子崩壊; 中間子型弱崩壊

The project consists of five major subjects which lead to the following achievements. (1) The microscopic three- and four-body cluster model calculations have been carried out for spectroscopy of light hypernuclei : The shrinkage of the nuclear core under the effect of Λ participation has been confirmed. The role of spin-spin and spin-orbit ΛN interactions has been analysed. It has been revealed that the admixture of Σ component into the mass-4 Λ hypernuclear low-lying states has a characteristic role reflecting the properties of YN interaction adopted. The in-flight and stopped (K-, π) reaction spectra are successfully explained by the DWIA calculation. (2) Several theoretical attempts have been presented to evaluate the production rates of double-Λ hypernuclei. The effect of hyperon mixing has been also investigated in typical S = -2 systems. (3) It is remarkable that several meson theoretical models of new YN and YY interactions have been presented to be tested in the hypernuclear structure. Moreover the quark models also presented several versions of the baryon-baryon interactions. The quark model has been extended to evaluate the interaction of the H particles in nuclear matter. (4) In order to explain new experimental data of hypernuclear weak decays (lifetimes), the correlated two-pion exchange process and the direct (quark process were evaluated in addition to the OPE process. It has been found that they have both certain favorable effects but are not always sufficient. (5) The important calculational methods have been applied and developed in the research project : the typical examples are the quantum molecular dynamics (QMD) approach, the Gaussian basis coupled-rearrangement channel method and the complex scaling method.

该项目由五个主要课题组成，取得了以下成果。(1)用微观三体和四体集团模型计算了轻超核的谱学：证实了在Λ参与作用下核芯的收缩。分析了自旋-自旋和自旋-轨道ΛN相互作用的作用。结果表明，在质量为4 Λ的超核低激发态中掺入π分量具有反映YN相互作用性质的特征作用.用DWIA计算成功地解释了飞行和停止的（K-，π）反应谱。(2)已经提出了几种理论尝试来评估双Λ超核的产生率。在典型的S = -2系统中，超子混合效应也被研究。(3)值得注意的是，已经提出了几种新的YN和YY相互作用的介子理论模型来在超核结构中进行检验。此外，夸克模型还提出了重子-重子相互作用的几个版本。本文将夸克模型推广到计算核物质中H粒子的相互作用。(4)为了解释超核弱衰变（寿命）的新实验数据，除了OPE过程外，还对相关的2 π交换过程和直接夸克过程进行了评价。已经发现，它们都具有某些有利的效果，但并不总是足够的。(5)重要的计算方法在研究中得到了应用和发展：典型的例子有量子分子动力学方法、高斯基耦合重排通道方法和复标度方法。

项目成果

T.Ueda, et al.: "ΛN and ΛΛ interactions in an OBE model and hypernuclei" Genshikaku Kenkyu. 41. 119-125 (1997)

T.Ueda 等人：“OBE 模型和超核中的 ΛN 和 ΛΛ 相互作用”Genshikaku Kenkyu。41. 119-125 (1997)

T.Yamada, et al.: "Double-Λ,twin-Λ and single-Λ hypernuclear productions for stopped Ξ^- particles in ^<12>C" Physical Review C. 56. 3216-3230 (1997)

T. Yamada 等人：“^ 12 C 中停止的 Ξ^-粒子的双-Λ、双-Λ 和单-Λ 超核生产”物理评论 C. 56. 3216-3230 (1997)

T.Sakai, et al.: "The interaction between H-dibaryons" Nuclear Physics A. 625. 192-206 (1997)

T.Sakai 等人：“H-二重子之间的相互作用”核物理 A. 625. 192-206 (1997)

Y.H.Koike et al: "Structure of the A=3 Σ-Hypernuclei" Nucl. Physics. A611. 461-483 (1996)

Y.H.Koike 等人：“A=3 Σ-超核的结构”，物理学 A611。

M. Oka: "πィイD1+ィエD1 Emission from Hypernuclei and the Weak ΔI = 3/2 Transitions"Nuclear Physics. A647. 97-104 (1999)

M. Oka：“超核的 πiD1+IeD1 发射和弱 ΔI = 3/2 跃迁”核物理 A647（1999）。