An Investigation of Positronium-Hydrogen Collision

Elastic positronium-hydrogen (Ps-H) scattering is of interest as it is a fundamental four-body Coulomb process. Using the complex Kohn variational method, we compute the phase shifts for elastic Ps-H scattering for the six lowest partial waves [1,2]. The $^{1,3}S$- and $^{1,3}P$-wave phase shifts can be viewed as benchmark results. Using a quantum defect theory [3], we determine $^{1,3}S$ and $^{1,3}P$ scattering lengths and $^{1,3}S$ effective ranges. We also compute elastic integrated, elastic differential and momentum-transfer cross sections.\\[4pt] [1] Denton Woods, S.~J.~Ward and P.~Van~Reeth, {\it unpublished} (2015).\\[0pt] [2] Denton Woods, P.~Van~Reeth and S.~J.~Ward, http://meetings.aps.org/link/BAPS.2014.DAMOP.Q1.55.\\[0pt] [3] Bo~Gao, Phys. Rev. A {\bf 58}, 4222 (1998).