核ANC和激发态中子晕  

Nuclear Asymptotic Normalization Coefficientsand Neutron Halo of the Excited States

作　　者：刘祖华[1] 林承键[1] 张焕乔[1] 李志常[1] 张竟上 吴岳伟[1] 杨峰[1] 阮明[1] 刘建成[1] 李淑媛 彭绍华 

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《高能物理与核物理》2002年第7期696-702,共7页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金 ( 1 9875 0 78;1 0 0 75 0 77);国家重点基础研究发展规划 (G2 0 0 0 0 774 0 6 )资助~~

摘　　要：利用转移反应1 1 B(d ,p) 1 2 B和1 2 C(d ,p) 1 3C抽取1 2 B 1 1 B +n和1 3C 1 2 C +n重叠函数的核渐近归一化常数 ,计算了1 2 B和1 3C核中价中子密度分布的均方根半径及其在核外的几率 .实验结果表明 ,1 2 B的第二 (Jπ=2 - ) ,第三 (Jπ=1 - )激发态和1 3C的第一 (Jπ=1 2 +)激发态为中子晕态 ,而1 3C的第三 (Jπ=5 2 +)激发态是中子皮态 .考察了库仑势和角动量对晕形成的阻碍效应 .We have extracted the nuclear asymptotic normalization coefficients for the virtual transitions 12B 11B+n and 13C 12C+n via two transfer reactions 11B(d, p) 12B and 12C(d, p) 13C. With these coefficients, root-mean-square radii for the valence neutron in 12B and 13C have been calculated. Our results show that the second (J π=2 -), third (J π=1 -) excited states in 12B, and the first (J π=1/2 +) excited state in 13C are neutron halo states, whereas the third (J π=5/2 +) excited state in 13C is a neutron skin state. The retard effects of the Coulomb potential and the orbital angular momentum on halo formation have been quantitatively examined. A unified scaling law for the mean-square radius versus the effective nucleon separation energy is established for the systems with a neutron or proton in a weekly bound state.

关 键 词：核ANC 转移反应 渐近归一化常数 激发态 中子晕 晕核 标度定律 原子核物理 核反应 中子皮态 

分 类 号：O571.4[理学—粒子物理与原子核物理]