Many-Body Enhancement Effects on the 2D ACAR in Chromium

抄録

The electron-positron many-body enhancement effect on the two-dimensional angular correlation distribution of positron annihilation radiation (2D ACAR) inchromium is phenomelogically investigated. The enhancement parameters are determined so as to obtain the best fit of the theoretical 2D ACAR to the experimental one. Two kinds of enhancement are considered. The first is a state-dependent one. In this scheme two enhancement factors are used for s–p electrons and d-electrons. For a hybridized state the value of enhancement is decided by a weighted mean of those two factors according to their partial populations in the state. The other is a character dependent one. In this scheme two enhancement factors are also used, but they are used to scale the partial wave functions in the electron wave coupled to the positron. The result using the character-dependent enhancement is very good, while that using the state-dependent one is not so good.