Department of Physics, Stockholm University, Stockholm, SE-106 91, Sweden.
Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
Phys Rev Lett. 2018 Aug 24;121(8):083401. doi: 10.1103/PhysRevLett.121.083401.
We have measured total absolute cross sections for the mutual neutralization (MN) of O^{-} with O^{+} and N^{+}. A fine resolution (of about 50 meV) in the kinetic energy spectra of the product neutral atoms allows unique identification of the atomic states participating in the mutual neutralization process. Cross sections and branching ratios have also been calculated down to 1 meV center-of-mass collision energy for these two systems, with a multichannel Landau-Zener model and an asymptotic method for the ionic-covalent coupling matrix elements. The importance of two-electron processes in one-electron transfer is demonstrated by the dominant contribution of a core-excited configuration of the nitrogen atom in N^{+}+O^{-} collisions. This effect is partially accounted for by introducing configuration mixing in the evaluation of coupling matrix elements.
我们已经测量了 O^{-}与 O^{+}和 N^{+}的相互中性化（MN）的总绝对截面。产物中性原子的动能谱中的精细分辨率（约 50 MeV）允许唯一识别参与相互中性化过程的原子态。我们还使用多通道 Landau-Zener 模型和离子-共价耦合矩阵元的渐近方法，计算了这两个系统的 1 MeV 质心碰撞能量以下的截面和分支比。在 N^{+}+O^{-}碰撞中，氮原子的芯激发构型的主要贡献表明了双电子过程在单电子转移中的重要性。通过在耦合矩阵元的评估中引入构型混合，可以部分解释这种效应。
