Selective enhancement of different electron populations by electron-positron attraction: application to zinc

Abstract

Curves for 2D ACPAR have been computed on the basis of LAPW band structure calculations and compared with experimental data. A new approach to enhancement was proposed based on a Thomas-Fermi type approximation. This treatment resulted in improving the agreement between theory and experiment by a factor of about three (as concerns the relative contribution of d- and s-electrons to positron annihilation) in comparison with the independent particle model. In order to extract information about the physical effects responsible for the residual differences between theory and experiment the isotropic average of the electron-positron density rho 0(p) was computed from the experimental data using the Cormack method and compared with theoretical predictions.