Study of Many-Particle Correlation in Structure and Reactions of Light Exotic Nuclei

1.不稳定核中多粒子关联的研究在14C+n+n模型中，研究了抑制16C中电子E_2从激发态到基态跃迁的机制。充分考虑了通过真实势能相互作用的两个中子的相关运动。阐明了自旋三重态在抑制机制中的作用。与实验的比较表明，~(14)C的壳层闭合假设可能并不完美，但人们必须考虑在一定程度上考虑核激发的可能性，以便更全面地理解这个问题以及15C2中的E_2跃迁。研究不稳定核的反应机理，开发了一个计算机程序，以便于计算由一个核和一个价中子组成的不稳定核引起的各种反应截面。横截面…更多的是可计算的，包括弹性散射，包括核的分裂效应和分裂后核的动量分布。所用的基本理论是伊克诺尔近似。为了使eikonal近似适用于像208pb这样的重靶，理论中必须包含一个无发散的振幅。将eikonal模型与库仑激发的微扰理论相结合，用蒙特卡罗积分技术证明了完整计算Glauber多次散射振幅的可行性。3.轻超核结合机制和重子-重子相互作用的研究通过显式考虑Λ耦合，解决了A=3-5ΛΣ超核这个长期存在的问题，也就是在基态能量系统学中观察到的超束缚。张量力在这个问题中起了至关重要的作用。用京都-新泻小组发展的夸克模型得到的势研究了^9_ΛBe和^6_&lt；ΛΛ&gt；He等较大的系统。在这项研究中，发展了一个新的框架，以使非定域，依赖于能量的夸克模型势在结构计算中的应用成为可能。较少

We summarize the results according to the main subjects of research.1.Study of many-particle correlation in unstable nucleiA mechanism for suppressing the electric E2 transition from the excited state to the ground state in 16C was studied in a 14C+n+n model. The correlated motion of the two neutrons, which interact via a realistic potential, was taken into account fully. The role of spin-triplet component in the suppression mechanism was clarified. A comparison with experiment showed that the assumption of shell closure for 14C may not be perfect but one has to consider the possibility of including the core excitation to some extent, in order to obtain more complete understanding of the issue together with the E2 transition in 15C.2.Study of reaction mechanism with unstable nucleiA computer code was developed to facilitate a calculation of various reaction cross sections induced by unstable nuclei, which is assumed to consist of a core nucleus and a valence neutron. The cross sections … More which are calculable cover the elastic scattering including the breakup effects of the nucleus and the momentum distribution of the core after the breakup. The basic theory employed was an eikonal approximation. To make the eikonal approximation applicable for a heavy target such as 208Pb, a divergence-free amplitude had to be incorporated in the theory. This was performed combining the eikonal model with the perturbation theory of the Coulomb excitation.A feasibility of a complete calculation of the Glauber multiple scattering amplitude was demonstrated with the use of Monte Carlo integration technique. This technique will open a way to describe high-energy reactions using correlated wave functions of high accuracy.3.Study of the binding mechanism of light hypernuclei and the baryon-baryon interactionsA long-standing problem of A=3-5 Λ hypernuclei, the overbinding observed in the systematics of the ground state energies, were resolved by taking into account the ΛΣ coupling explicitly. The tensor force played an essential role in this problem. Larger systems such as ^9_ΛBe and ^6_<ΛΛ>He were studied with the potentials derived from a quark-model developed by Kyoto-Niigata group. In this study, a new framework was developed in order to make the application of the non-local, energy-dependent quark-model potentials possible in structure calculations. Less