Molecular effects on antiproton capture by H-2 and the states of (p)over-bar-p formed
Molecular effects on antiproton capture by H-2 and the states of (p)over-bar-p formed
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DOI：
10.1103/physreva.56.3583
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发表时间：
1997-11-01
影响因子：
2.9
通讯作者：
Cohen, JS
中科院分区：
文献类型：
--
作者：
Cohen, JS
使用 Kirschbaum-Wilets 方法（属于一类有时称为费米子分子动力学的准经典方法）的推广，对氢分子 (H-2) 捕获的反质子（(p) over bar）进行了完整的五体动力学计算。发现 H-2 和 H 原子捕获之间的差异是巨大的。两中心结构、旋转运动和振动运动的影响是有区别的。特别重要的是，振动自由度使分子能够捕获实验室能量高于 100 eV 的反质子，而原子捕获在高于 27 eV 的电离阈值（在实验室系统中）时急剧截止。原子的反质子捕获通过相同的方法以及仅适用于原子的经典轨迹蒙特卡罗方法计算。发现所形成的初始量子数（准经典分配）被转移到分子目标的明显较小的值；与原子目标相比，分子目标的 n 分布也更窄。 [S1050-2947(97)05011-7]。
Complete five-body dynamical calculations of antiproton ((p) over bar) capture by the hydrogen molecule (H-2) have a been carried out using a generalization of the Kirschbaum-Wilets method (belonging to a class of quasiclassical methods sometimes called fermion molecular dynamics). The differences between capture by H-2 and the H atom are found to be dramatic. The effects due to the two-center structure, rotational motions, and vibrational motions are distinguished. Of particular importance, the vibrational degree of freedom enables the molecule to capture antiprotons having lab energies above 100 eV, whereas atomic capture cuts off sharply above the ionization threshold of 27 eV (in the lab system). Antiproton capture by the atom is calculated by the same method as well as by the classical-trajectory Monte Carlo method, which is applicable only to the atom. The initial quantum numbers (assigned quasiclassically) of the formed are found to be shifted to significantly smaller values for the molecular target; the n distribution is also narrower for the molecular target as compared with the atomic target. [S1050-2947(97)05011-7].