Theoretical Study on Nuclear Interaction based on Rigourous Calculations of Few-Nudeon Systems

1.三核子散射中的三核子力效应：通过分析自旋空间中核子-氘核散射振幅的结构*，我们得到了一些极化观测值的组合，从中获得了核力自旋依赖性的滞留信息。然后，对为了消除实验数据与结合能或微分截面计算之间的系统差异而引入的三核子力的自旋依赖性进行了批判性研究。库仑少体问题的研究：由于三体或三体以上量子系统纯库仑问题的解析解未知，因此解决库仑力作用的少核子系统问题并不容易。我们成功地开发了低能下三体问题的高精度计算程序。这样就可以进行低能质子-氘核散射的分析，而不存在处理库仑力时的模糊性。利用该计算程序阐明了三核子散射中电荷对称破缺的影响。在此基础上，推导了库仑力作用下的四体问题的计算公式。超子-核子散射中的极化观测：对重子相互作用中所谓核力问题的理解有望得到更深入的认识。我们研究了散射观测值与自旋相关的超子-核子相互作用（如自旋-自旋和自旋-轨道力）之间的关系。发现了一些反映自旋依赖相互作用特征的偏振观测值组合。采用几种电位模型进行了数值分析，并与实验数据进行了比较。

1.Three-nucleon-force effects in three-nucleon scattering : By analyzing the structure* of nucleon-deuteron scattering amplitude in the spin space, we obtain some combinations of polarization observables from which detained information on the spin dependence of nuclear forces is acquired. Then, the spin dependence of three-nucleon forces, which were introduced in order to cancel the systematic disagreement between experimental data and calculations of binding energy or differential cross-sections, was critically investigated.2.Research of the Coulomb few-body problem : Since analytic solution of a pure Coulomb problem for the quantum system of three or more bodies is not known, it is not easy to solve the problem of few-nucleon systems that Coulomb forces commit. We succeeded in development of the high precision calculation code of three-body problem at low energies. By this, it was enabled to perform analysis of low-energy proton-deuteron scattering without the ambiguity in handling of Coulomb force. Effect of charge symmetry breaking in three-nucleon scattering was clarified using this calculation code. Furthermore, calculation of the four-body problem which Coulomb forces commit was formulated.3.Polarization observables in hyperon-nucleon scattering : It can be expected to get deeper understanding to catch the problem of the so-called nuclear force as part of the interaction between baryons. We pursued the relation between scattering observables and the spin-dependent hyperon-nucleon interaction such as spin-spin and spin-orbit forces. Some combinations of polarization observables reflecting the feature of these spin dependent interactions were found out. Numerical analysis using some potential models was performed to compare with the experimental data that resent.