Study of Isospin dependence of mean field and vibration in unstable nuclei

我们用Hartree-Fock(HF)-BCS模型和在坐标空间中求解HF-Bogolyubov模型研究了不稳定核的配对关联。我们还研究了电四极激发和自旋激发的响应函数，适当地考虑了与连续谱的耦合。我们发现，响应函数对价中子的分离能非常敏感，当最后一个中子的分离能小于1 MeV时，响应函数在阈值以上有很大的增强。我们研究了Skyrme HF和相对论平均场模型中几种核物质性质之间的关联。利用平均场模型的各种Skyrme哈密顿量和拉格朗日量，发现了中子皮厚度、中子体压强和对称能系数之间的线性关系。同标量巨单极共振S的同向量核物质性质与同位旋依赖性之间的关联也是POI…更多的是出局。为了提取中子皮厚度和确定中子物质状态方程，研究了~(90)Zr和~(208)Pb的电荷交换自旋-偶极激发。在HF+随机位相近似(RPA)下研究了核不可压缩性与同位旋的关系。用三体模型研究了弱束缚核--6He和11Li-6He和11Li中的配对关联。我们指出，双中子型关联在这些原子核中起主导作用。通过计算核与两中子质心之间几个距离处的两个中子波函数，模拟了不同密度下的中子对的行为。我们发现双中子波函数与无限大核物质中库珀对波函数的BCS和BEC相类似。文中还将讨论库仑破裂截面，以探讨理论猜想。较少

We studied the paring correlations in unstable nuclei by Hartree-Fock(HF)-BCS mode and also HF-Bogolyubov model solving in the coordinate space. We studied also the response function of Electric quadrupole excitation and spin excitation taking into account the coupling to the continuum properly. We found that the response function is very sensitive to the separation energy of valence neutrons and shows a huge enhancement just above the threshold when the last neutrons have a very small separation energy less than 1MeV.We studied correlations among several nuclear matter properties in the Skyrme HF and relativistic mean field (RMF) models. Linear correlations are found between neutron skin thickness, the pressure of the neutron matter and also the symmetry energy coefficient using various Skyrme Hamiltonian and Lagrangians of mean field models. The correlations between the isovector nuclear matter properties and the isospin dependence of isoscalar giant monopole resonance s are also poi … More nted out. Charge exchange spin-dipole excitations of 90Zr and 208Pb are studied in order to extract the neutron skin thickness and to determine the neutron matter equation of states. The isospin dependence of the nuclear incompressibility is also studied in the HF+random phase approximation (RPA).The pairing correlations in weakly bound nuclei, so called Borromean nuclei, on the edge of neutron drip line, 6He and 11Li, is studied by using a three-body model in which two valence neutrons interact with each other by a density-dependent contact force. We pointed out the di-neutron type correlation play a dominant role in these nuclei. The behavior of the neutron pair at different densities is simulated by calculating the two neutron wave function at several distances between the core nucleus and the center of mass of the two neutrons. We found that the di-neutron wave function shows an analogy to the BCS and BEC phases of the Cooper pair wave functions found in the infinite nuclear matter. The Coulomb breakup cross sections will be also discussed to probe the theoretical conjectures. Less