Manybody theory for positronium scattering and pickoff annihilation in noblegas atoms
Abstract
The manybodytheory approach to positroniumatom interactions developed in [Phys. Rev. Lett. \textbf{120}, 183402 (2018)] is applied to the sequence of noblegas atoms HeXe. The Dyson equation is solved separately for an electron and positron moving in the field of the atom, with the entire system enclosed in a hardwall spherical cavity. The twoparticle Dyson equation is solved to give the energies and wave functions of the Ps eigenstates in the cavity. From these, we determine the scattering phase shifts and cross sections, and values of the pickoff annihilation parameter $^1Z_\text{eff}$ including shortrange electronpositron correlations via vertex enhancement factors. Comparisons are made with available experimental data for elastic and momentumtransfer cross sections and $^1Z_\text{eff}$. Values of $^1Z_\text{eff}$ for He and Ne, previously reported in [Phys. Rev. Lett. \textbf{120}, 183402 (2018)], are found to be in nearperfect agreement with experiment, and for Ar, Kr, and Xe within a factor of 1.2.
 Publication:

arXiv eprints
 Pub Date:
 May 2021
 arXiv:
 arXiv:2105.06749
 Bibcode:
 2021arXiv210506749S
 Keywords:

 Physics  Atomic Physics;
 Quantum Physics
 EPrint:
 22 pages