Collective correlations and excitation mechanism of nuclei near the drip-line : developments of cHFB linear response theory

1.用坐标空间HFB理论阐明了中等质量近滴线O、Ca和Ni同位素双中子关联的定量方面。两个自旋单重态中子在2-3fm的短程区是强关联的，相对几率达30- 50%。在远离核表面2-3fm的外部中子皮区，双中子关联增强最多。从组态混合和Hartree-Fock单粒子轨道的角度研究了双中子关联的微观结构.结果表明，具有高角动量和高准粒子能量的轨道有助于关联的形成。3.研究了超导相均匀核物质中的双中子关联。结果表明，在正常密度的1/5至1/100的低密度下，双中子相关性最显著。利用cHFB线性响应理论详细研究了软偶极激发的双中子特性（连续QRPA理论），以澄清占主导地位的粒子-粒子成分：分析了对软偶极激发有贡献的单粒子轨道，发现高角动量轨道的贡献很大，这表明，5.我们完成了一个连续QRPA理论的公式，它包含了自旋Skyrme相互作用的速度依赖部分独立激励模式

1.Quantitative aspects of the dineutron correlations in the medium mass near-drip-line O,Ca and Ni isotopes have been clarified by means of the coordinate space HFB theory. Two neutrons with spin singlet configuration are strongly correlated in the short distance region of 2-3fm, where the relative probability of the pair amounts up to 30-50%. The dineutron correlation is most enhanced in the external neutron skin region far outside the nuclear surface by 2-3fm. The correlation is found to exist also in the nuclear interior and in stable nuclei, indicating a generality of this correlation in nuclei.2.Microscopic structure of the dineutron correlation is investigated from the viewpoint of the configuration mixing and the Hartree-Fock single-particle orbits. It is clarified that the orbitals with high angular momenta and high quasiparticle energies contribute to formation of the correlation.3.The dineutron correlation in uniform nuclear matter in the superconducting phase has been investigated. It has been shown that the dineutron correlation is most significant at low densities with 1/5 to 1/100 of normal density. It is also shown that the dineutron correlation is quite general, being independent of the use of the zero or finite range forces.4.The dineutron character of the soft dipole excitation has been investigated in detail by means of the cHFB linear response theory (the continuum QRPA theory) in order to clarify the dominant particle-particle component : Analyzing the single-particle orbits contributing the soft dipole excitation, large contribution of high angular momentum orbittals is found, indicating that the di-neutron correlation plays a central role for this mode.5.We have completed a formulation of the continuum QRPA theory that incorporates the velocity dependent part of the Skyrme interaction for spin independent excitation modes.