Energy Relations of Positron-Electron Pairs Emitted from Surfaces.

The impact of a primary positron onto a surface may lead to the emission of a correlated positronelectron pair. By means of a lab-based positron beam we studied this pair emission from various surfaces. We analyzed the energy spectra in a symmetric emission geometry. We found that the available energy is shared in an unequal manner among the partners. On average the positron carries a larger fraction of the available energy. The unequal energy sharing is a consequence of positron and electron being distinguishable particles. We provide a model which explains the experimental findings. [ABSTRACT FROM AUTHOR]