Electron-He+P-wave elastic scattering and photoabsorption in two-electron systems

Abstract

In a previous paper [A. K. Bhatia, Phys. Rev. A 69, 032714 (2004)], electron-hydrogen $P$-wave scattering phase shifts were calculated using the optical potential approach based on the Feshbach projection operator formalism. This method is now extended to the singlet and triplet electron-${\mathrm{He}}^{+}$ $P$-wave scattering in the elastic region. Phase shifts are calculated using Hylleraas-type correlation functions with up to 220 terms. Results are rigorous lower bounds to the exact phase shifts, and they are compared to phase shifts obtained from the method of polarized orbitals and close-coupling calculations. The continuum functions calculated here are used to calculate photoabsorption cross sections. Photoionization cross sections of He and photodetachment cross sections of ${\mathrm{H}}^{\ensuremath{-}}$ are calculated in the elastic region---i.e., leaving ${\mathrm{He}}^{+}$ and H in their respective ground states---and compared with previous calculations. Radiative attachment rates are also calculated.