Schwinger Variational Approach for the Evaluation of Balmer-α Emission Cross Sections in Proton-Hydrogen Atom Collision at Intermediate Impact Energies

A variational impact parameter approach based on the Schwinger variational principle used to evaluate the Balmer-α excitation cross sections of hydrogen targets impacted by protons for incident energies ranging from 10 to 200 keV is here reported. The obtained total cross sections are compared to the available data, and the huge discrepancies between the existing theoretical predictions and the experimental measurements are pointed out.