Quasiparticle integral equations for the electron-hydrogen system

Abstract

Electron-hydrogen binding energy and scattering observables below the first excitation threshold are calculated with three-body integral equations reduced to effective two-body Lippmann-Schwinger-type equations by means of the quasiparticle method. The effective potentials occurring in this formulation are determined in lowest-order and in first-order quasi-Born approximation (QBA). In first-order QBA, our results are closely related to those obtained in the static exchange approximation. Polarization effects are only partly contained in the low-order quasi-Born-approximation terms considered, a fact discussed in the detailed analysis of our results.