Theoretical study of electronic transitions in relativistic heavy-ion collisions

由Toshima等人的研究可知，在非相对论耦合道方法中不需要特别考虑库仑长程相互作用。我们已经表明，这是不是相对论离子原子碰撞的情况下，扭曲波形式必须使用甚至耦合通道方法，以使过渡矩阵定义良好。基于扭曲波方法的数值计算表明，U^<92+>+U^<91+>系统的截面因这种效应而改变了两倍以上。对称程函近似是传统程函理论的对称化形式，由于公式简单，得到了广泛的应用。我们从解析和数值计算两方面指出对称程函公式不满足正确的库仑边界条件，并且由于这一缺陷而给出了非物理意义上的大自旋翻转截面。众所周知，第二或 ...更多信息 对于电子俘获过程，在高能量下DER贡献成为主导。结果，微分截面在临界角处显示出尖锐的峰，并且该峰被称为托马斯峰。虽然二阶项的优势意味着微扰理论本身的不足，但所有对托马斯机制的理论研究都是基于微扰理论。我们发展了一种新的基于高斯型轨道展开的耦合信道编码，并首次成功地用非微扰方法产生了托马斯峰。通过这项研究，它表明，托马斯峰移动到较小的散射角侧和三阶过程是由于多散射效应的贡献显着。此外，我们还对托马斯机理进行了经典轨线Monte Carlo计算，发现在纯经典处理中托马斯峰意外地缺失。第二玻恩项的精确计算也首次实现了重排碰撞到激发态和相消和建设性的干涉效应的报告。少

It is known from the study of Toshima and others that special account of the long-range of Coulomb interactions is not needed in the non-relativistic coupled-channel approach. We have shown that this is not the case for relativistic ion-atom collisions and distorted-wave formalism must be used even for coupled-channel method in order to make the transition matrix well-defined. It was demonstrated by numerical calculations based on the distorted-wave method that the cross sections for the system U^<92+>+U^<91+> change more than a factor of two by this effect. The symmetric eikonal approximation, which is a symmetrized version of the traditional eikonal theory, has been used widely because of the simplicity of the formula. We pointed out from both analytic and numerical calculations that the symmetric eikonal formula does not satisfy the correct coulomb boundary conditions and it gives unphysically large spin-flip cross sections owing to this defect. It is widely known that the second-or … More der contribution becomes dominant at high energies for electron capture processes. As a result the differential cross section shows a sharp peak at a critical angle and this peak is called the Thomas peak. Although the dominance of the second-order term implies the inadequacy of the perturbation theory itself, all of the theoretical studies for the Thomas mechanism were based on the perturbation theory. We developed a new coupled-channel code based on Gauss-type orbital expansion and succeeded in producing the Thomas peak by nonperturbative method for the first time. By this study it was demonstrated that the Thomas peak is shifted to smaller scattering angle side and a third-order process is contributing significantly owing to a multiscattering effect. Besides we carried out the classical trajectory Monte Carlo calculation for the Thomas mechanism and showed that the Thomas peak is unexpectedly missing in the pure classical treatment. Exact calculation of the second-Born terms was also realized for the first time for rearrangement collisions into exited states and destructive and constructive interference effects were reported. Less