Landau-Zener Effects in Nuclear Heavy-Ion Reactions

1.研究了核重离子碰撞中的朗道-齐纳能级交叉是否会引起跃迁截面的类共振增强。半经典的估计已经表明，由首席研究员，以增强截面对应的实验。量子力学计算已经用一个简单的两能级模型进行了，但结果只给出了轻微的增强。为了理解这种差异，现在正在进行分析处理，例如DWBA。为了进行上述研究，我们开发了一种新的形式主义，即，提出了一种在物体固定坐标系下的散射形式，使我们能够适应两中心壳模型的散射问题.此外，我们还对分子共振的振转模型进行了严格的研究。已经表明，忽略旋转-振动耦合会导致完全误导的结果。

1. Investigations have been made on whether Landau-Zener level crossings in nuclear heavy-ion collisions cause resonance-like enhancements in transition cross sections. Semi-classical estimates were already shown by the head investigator to give enhanced cross sections corresponding to experiments. Quantum mechanical calculations have been performed with a simple two-level model, but have turned out to give only slight enhancements. In order to understand this difference, analytical treatments are now being pursuites, for example, by DWBA.2. In order to perform the above investigations, we have developped a new formalism, i.e., a scattering formalism in the body-fixed frame, which enables us to accomodate 2-center shell model in scattering problem.3. Furthermore, we have critically investigated the vibration-rotation models for molecular resonances. It has been shown that neglects of rotation-vibration couplings cause completely misleading results.