Theoretical Studies of Polarization Phenomena in Nuclear Reactions at Intermediate energies

通过中能核反应中的极化现象，研究了与自旋相关的相互作用和反应机理。得到的主要结果如下：1)利用不变振幅方法，成功地将氚的弹性散射振幅分解成对应于每个与自旋相关的相互作用的自旋分类振幅。这阐明了氚-核相互作用包括中心张量、LS张量、T_R型张量和T_L张量相互作用，最后一种张量是由包含虚破裂效应的LS相互作用的二阶反应产生的。1)(d，p)中的方法被推广到(d，p)反应，从而适用于(d，p)反应。特别是对九州大学串列装置所获得的低能实验数据的分析是相当成功的。3)d^&lt；-&gt；+p^&lt；-&gt；-&gt；^3He+pi^0反应将不变振幅方法应用于d^&lt；-&gt；+p聚变质子的产生。从Rheta=0和阈值pi处的张量分析功率出发，导出了关于pi-N散射的S波散射长度的重要信息，并阐明了传统的散射长度数据在精度上是值得怀疑的。4)用Faddeev方法分析核反应。本文尝试将Faddeev方法应用于普通的氢核弹性散射，得到了N-^lt；12&gt；C可分势。

Spin-dependent interactions and reaction mechanisms are investigated through polarization phenomena in nuclear reactions at intermediate energies. The main results obtained are as follows.1) Elstic scattering of deuterons Scattering amplitudes are successfully decomposed into spin-classified amplitudes which correspond to each spin-dependent interactions, by the help of the invariant-amplitude method. This clarifies that the deuteron-nucleus interaction consists of the central, LS, T_R-type tensor and T_L-type tensor interactions, the last one being produced by the second- order of the LS interaction which includes the virtual-breakup effect.2) (d,p) reactions The method in 1) is extended so as to be applicable to (d,p) reactions, for which some important theoretical predictions are made by the present formalism for polarization observables. Particularly, the theory is quite successful in the analyses of the low-energy experimental data which have been obtained in Kyushu University Tandem Facilities.3) d^^<->>+p^<->> ^3He+pi^0 reaction The invariant-amplitude method is applied to d^^<->>+p fusion pion production. From the tensor analyzing power at rheta = 0 and pi at the threshold, the important information on the S-wave scattering length of pi-N scattering is derived and it is clarified that the conventional data on the scattering length are quite doubtful in the precision. The extension of such investigations to higher energies is now in progress by the computer work.4) Analyses of nuclear reactions by the Faddeev method The application of the Faddeev method to the ordinary deuteron elastic scattering by a nucleus is attempted and the N-^<12>C separable potential is now obtained.