Neutron Halo Structure in exiotic nuclei (^<17>B,^<22>N,^<23>O etc.)

异质核中的中子晕结构（^<17>B、^<22>N、^<23>O 等）

• 批准号: 13440075
• 负责人: SUZUKI Takeshi
• 金额: $ 9.34万
• 依托单位: Saitama University (2003)Niigata University (2001-2002)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440075/
• 关键词: Neutron Halo; Skin structure; Momentum distribution; Glauber model; Shell mixing; Reaction cross section; Density distribution; 入射核破砕反応; グフウバー模型; 殻模型; 相互作用断面積; 不安定核; 殻膜型

The two--neutron removal cross section (σ_<-2n>) and the longitudinal momentum distribution of ^<15>B fragments from the breakup of ^<17>B on ^9Be were measured at 70 A MeV. The distribution in the projectile rest frame is characterized by a FWHM of 80±10 MeV/c for ^<15>B. The σ_<-2n> is found to be 0.22±0.05 b. A Glauber--type analysis of the data provides clear evidence of a two-neutron halo structure in ^<17>B.The reaction cross section (σ_R) for the neutron-rich nucleus ^<17>B on a carbon target has been measured at an energy of 77 AMeV by a transmission method. A large enhancement of σ_R was observed (1400mb). The density distribution of ^<17>B was deduced through the energy dependence of σ_R together with high-energy data using a finite-range Glauber model calculation under an optical limit approximation. It is confirmed that the neutron-tail in the density distribution is necessary for ^<17>B in order to reproduce the measured σ_R. Based on the assumption of a core (^<15>B) plus valence two-neutron picture, the mixture of v (2s_<1/2>) and v (1d_<5/2>) was studied without treating the correlation between two neutrons.

在70 A MeV下测量了^<17>B在^9Be上破碎后的双中子去除截面（σ_<-2n>）和^<15>B碎片的纵向动量分布。对于^<15>B，弹体静止架内的分布特征为FWHM为80±10 MeV/c。σ_<-2n>为0.22±0.05 b。数据的Glauber型分析提供了^<17> b中存在双中子晕结构的明确证据。用透射法测量了富中子核^<17>B在碳靶上的反应截面（σ_R），能量为77 AMeV。σ_R有较大的增强（1400mb）。在光学极限近似下，利用有限范围Glauber模型计算，通过σ_R的能量依赖性和高能数据，推导出^<17>B的密度分布。证实了密度分布中的中子尾对于^<17>B是必要的，以便再现测量到的σ_R。在假设核(^<15>B) +价态双中子图的基础上，研究了v （2s_<1/2>）和v （1d_<5/2>）的混合物，而不考虑两个中子之间的相关性。

项目成果

R.Kanunngo et al.: "Expeimnenat1 Evidence of Core M oclilfication in the Near Drip-Line Nucleus ^<23>O"Physical Revew Letters. 88. 142502-1-142502-4 (2002)

R.Kanunngo 等人：“近滴线核 ^<23>O 中核心运动的实验证据”物理评论快报。

Y.Yamaguchi et al.: "Halo structure of ^<17>B studied via its reaction cross sectrion"AIP conference Proc.. 印刷中. (2004)

Y. Yamaguchi 等人：“通过反应截面研究^ 17 B 的晕结构”AIP 会议论文集（2004 年）。

Y.Yamaguchi et al.: "Halo structure of ^<17>B studied via its reaction cross section"AIP conference Proc.. (印刷中). (2004)

Y. Yamaguchi 等人：“通过反应截面研究^ 17 B 的晕结构”AIP 会议记录（2004 年出版）。

A.Ozawa et al.: "Measurements of Interaction Cross sections or Ar and Cl isotopes"Nuclear Physics. A・709. 60-70 (2002)

A. Ozawa 等：“Ar 和 Cl 同位素相互作用截面的测量”核物理 A·709（2002 年）。

R. Kanunngo: "Experimental evidence of core modification in the near drip-fine nucleus ^<23>O"Physical Review Letters. (2001)

R. Kanunngo：“近滴细核^<23>O中核修饰的实验证据”物理评论快报。