A Harris-Method Calculation of Electron and Positron Scattering by Hydrogen Atoms

The Harris method of obtaining scattering phase shifts is applied to the s-wave elastic electron and positron scattering by hydrogen atoms by use of Schwartz-type correlated trial functions with 50 and 56 terms, respectively. Kohn-method calculations with the same trial functions are also carried out at the same energies. The agreement between the Harris-method results and the Kohn-method results is good especially at low energies. In the electron-scattering case, two kinds of errors cancel each other to some extent, but in the positron case, they add up to make the agreement between the Harris-method and Kohn-method results somewhat worse.