Di-neutron correlation and soft dipole excitation in medium mass neutron-rich nuclei near drip line
Di-neutron correlation and soft dipole excitation in medium mass neutron-rich nuclei near drip line
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DOI：
10.1103/physrevc.71.064326
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发表时间：
2004-08
影响因子：
3.1
通讯作者：
M. Matsuo;K. Mizuyama;Y. Serizawa
中科院分区：
文献类型：
--
作者：
M. Matsuo;K. Mizuyama;Y. Serizawa
本文从双中子关联的观点出发，研究了中质量核中滴线附近的中子配对关联和软偶极激发。基于坐标空间Hartree-Fock-Bogoliubov方法和连续准粒子无规相近似，对偶-偶{sup 18-24}O，{sup 50-58}Ca和{sup 80-86}Ni进行了数值分析.在基态中发现了双中子关联的明显特征;两个中子在短的相对距离<或约<20 μ m处关联。2 fm，大概率为{approximate} 50%。软偶极激发强烈地受中子对关联的影响，并伴随着大的中子对运动跃迁密度。这种行为起源于相干叠加的两个准粒子配置[lx（1 +1）]{子L=1}组成的连续态与高轨道角动量l达到1 {approx}10的顺序。结果表明，在中子配对影响下的偶极软激发是以核外双中子对剩余A-2子系统的运动为特征的。讨论了有效对力对密度依赖性的敏感性。
The neutron pairing correlation and the soft dipole excitation in medium mass nuclei near the drip line are investigated from the viewpoint of the di-neutron correlation. Numerical analyses based on the coordinate-space Hartree-Fock-Bogoliubov method and the continuum quasiparticle random phase approximation are performed for even-even {sup 18-24}O,{sup 50-58}Ca, and {sup 80-86}Ni. A clear signature of the di-neutron correlation is found in the ground state; two neutrons are correlated at short relative distances < or approx. 2 fm with large probability {approx}50%. The soft dipole excitation is influenced strongly by the neutron pairing correlation, and it accompanies a large transition density for pair motion of neutrons. This behavior originates from a coherent superposition of two-quasiparticle configurations [lx(l+1)]{sub L=1} consisting of continuum states with high orbital angular momenta l reaching an order of l{approx}10. It suggests that the soft dipole excitation under the influence of neutron pairing is characterized by the motion of di-neutron in the nuclear exterior against the remaining A-2 subsystem. Sensitivity to the density dependence of the effective pair force is discussed.