轻奇特核结构中的核心激发——以^(11)Be为例

Core Excitation in Light Exotic Nuclear Structure—— Taking ^(11)Be for Example

近年来,越来越多的实验表明,很多轻奇特核结构中都有核心激发成分。本研究以丰中子晕核^(11)Be为例,介绍核心激发成分的实验和理论研究进展,重点阐述核心激发成分对直接核反应微分截面的影响。实验上,1n移除反应及^(11)Be(p,d)和^(10)Be(d,p)转移反应是测量^(11)Be核心激发成分比例的典型实验类型。理论上,发展了能够包括^(11)Be核心激发成分的Faddeev AGS方法,XDWBA方法以及XCDCC方法。加入核心激发成分后,这些模型的计算结果可以更加合理地描述^(11)Be在各种靶上的弹性散射和碎裂微分截面。通过对比是否包含核心激发成分的计算结果,发现其影响主要体现在弹散微分截面的大质心系角度,以及(p,d)转移反应角分布的小质心系角度。另外,对Ex=0.5～3 Me V的激发能区的碎裂反应,核心激发的影响不可忽略;对Ex=3～5.5 Me V的碎裂反应,核心激发的贡献非常重要。

It was found that many light exotic nuclei have the core-excitation components. In this paper,taking one-neutron halo nucleus11 Be for example, the experimental and theoretical research progress, as well as the influences on the direct nuclear reaction differential cross sections of this exotic component were reviewed.The 1n removal,11Be（p, d） and10Be（d, p） transfer reactions are typical experimental methods to investigate this component. The Faddeev AGS, the XDWBA, and the XCDCC methods are developed to include this constituent in various theoretical models. With the core-excitation component, the calculated results can more reasonably describe the elastic scattering and breakup differential cross sections of11 Be impinging on various targets. Comparing the full XCDCC calculation with that omitting core-excitation effect, we found that this component mainly affects the elastic scattering differential cross sections at large center-of-mass angles, and the（p, d） transfer reaction angular distributions at small center-of-mass angles. In addition, its effect is non-negligible for the breakup reaction within the excitation energy interval of Ex = 0.5 3 Me V, and is remarkable for Ex = 3 5.5 MeV.