Do positrons measure atomic and molecular diameters?
Do positrons measure atomic and molecular diameters?
复制标题
正电子可以测量原子和分子直径吗？
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
G. Karwasz
中科院分区：
文献类型：
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作者：
J. Franz;K. Fedus;G. Karwasz
摘要
报道了正电子与氩、氪、氮和甲烷碰撞的弹性积分散射截面的密度泛函计算。长程渐近极化势是用高阶项来描述的，远远超过了诱导偶极势（−α/r4），而短程相互作用则是用两种不同形式的电子-正电子相关势（Borovski-Nieminen势和量子蒙特卡罗势）来模拟的。这两种方法的结果都与最近的理论值和实测值吻合得很好。根据目前和以前的理论和实验数据，我们讨论了一些系统的积分散射截面低于正电子素形成阈值观察。特别指出了散射截面值与原子尺度之间的相关性。
图形摘要
Abstract
We report on density functional calculations (DFT) of elastic integral scattering cross-sections for positron collisions with argon, krypton, nitrogen and methane. The long-range asymptotic polarization potential is described using higher-order terms going much beyond an induced dipole potential (−α/r4) while the short-range interaction is modeled by two different forms of electron – positron correlation potential (Boroński-Nieminen and Quantum Monte Carlo potentials). The results of both approaches agree quite well with the recent theoretical and measured values. Based on the present and previous theoretical and experimental data we discuss some systematics observed in integral scattering cross-sections below the positronium formation threshold. In particular we point out on the correlation between the values of scattering cross-sections and atomic dimensions.
Graphical abstract
影响因子：
8.6
作者：
Drummond, N. D.;Rios, P. Lopez;Pickard, C. J.
通讯作者：
Pickard, C. J.