Positronium-hydrogen scattering using the stochastic variational method

Abstract

The stochastic variational method (SVM) is used in conjunction with stabilization ideas in order to compute low-energy phase shifts. The method is tested by applying it to a simple model problem, and to s-wave positron-hydrogen scattering. The SVM is then applied to the calculation of the s- and p-wave phase shifts for Ps-H scattering. The scattering lengths obtained were ${4.34a}_{0}$ for the electronic-spin-singlet state and ${2.22a}_{0}$ for the triplet state. The present scattering lengths are probably accurate to $\ifmmode\pm\else\textpm\fi{}3%$ and are the most accurate that have so far been computed for the Ps-H systems.