质子碰撞氦原子单电离全微分截面的后碰撞作用和扭曲效应

用扭曲波方法，推广了修正的库仑波恩（MCB）近似计算到重离子碰撞He原子电离问题计算。检查了对75keV 质子碰撞氦原子单电离的全微分截面的应用情况。结果表明，现在的方法定性地产生了实验的峰结构，尤其是在垂直平面。应用MCB方法研究这一碰撞体系中的后碰撞(PCI)效应，发现PCI效应对全微分截面的形状在散射平面和垂直平面都有着强烈的影响。同时，分析了扭曲效应对全微分截面的贡献。表明，随着动量转移的增加，扭曲效应的作用变得越来越重要。尤其是，扭曲效应定性解释了负角区域的结构。

Postcollision interaction and distorted effects on fully differential cross sections for single ionization of helium by proton impact

The modified Coulomb-Born (MCB) approximation is applied to study single ionization of helium by 75 keV proton impact. Fully differential cross-sections (FDCS) are calculated using the MCB theory in both the scattering plane and the perpendicular plane for the first time. The results are compared with the experimental data and the MCB without postcollision interaction (MCB-noPCI) calculations. It is found that the present MCB calculations qualitatively reproduce the experimental peak structures, especially in the perpendicular plane. And the PCI has a profound impact on the shape of the fully differential cross section in both the scattering plane and the perpendicular plane. The contribution of the distorted effects to the FDCS is also analyzed in the scattering and perpendicular planes. It turns out that, with the increasing momentum transfers (difference between the initial and scattered projectile momentum), the role of the distorted effects becomes more and more important. In particular, the distorted effects qualitatively predict the structures at negative angles region at all momentum transfers in the scattering plane.