Annihilation momentum densities and correlation enhancement factors for
low-energy positron annihilation on valence and core electrons of noble-gas atoms
are calculated using many-body theory. s, p and d-wave positrons of momenta up to
the positronium-formation threshold of the atom are considered. The enhancement
factors parametrize the effects of short-range electron-positron correlations which
increase the annihilation probability beyond the independent-particle approximation.
For all positron partial waves and electron subshells, the enhancement factors
are found to be relatively insensitive to the positron momentum. The enhancement
factors for the core electron orbitals are also independent of the positron angular
momentum. The largest enhancement factor (∼ 10) is found for the 5p orbital in
Xe, while the values for the core orbitals are typically ∼ 1.5.
|Title of host publication||[Volume Title TBA]|
|Publication status||Accepted - 11 Sep 2017|
|Name||Progress in Theoretical Chemistry and Physics|