On the reliability of various enhancement theories for a description of electron-positron densities in metals

TL;DR

This paper compares four theoretical models for electron-positron momentum densities in metals against experimental 3D data, finding that the Bloch-modified ladder theory best qualitatively matches the observations across different metals.

Contribution

It evaluates and contrasts various enhancement theories for electron-positron densities, highlighting the effectiveness of the Bloch-modified ladder theory in describing experimental data.

Findings

Bloch-modified ladder theory qualitatively matches all tested metals

Other approaches fail to accurately describe the MDAP profiles

The study advances understanding of electron-positron interactions in metals

Abstract

Four theoretical approaches to calculate momentum densities of electron-positron annihilation pairs (MDAP) in crystalline solids are confronted with 3D densities reconstructed from two-dimensional angular correlation (2D-ACAR) data for copper, chromium, and yttrium. It is shown that the Bloch-modified ladder theory, in contrast to other approaches, is able to describe - at least qualitatively - the MDAP profiles for all metals investigated.