On a unified description of the profile of the resonance 2s21S of helium in proton-helium collisions (33 keV-500 keV)

The authors propose a method which clarifies the complicated results obtained for the Shore parameter a and the Fano parameter q, by a parametrization of energy spectra of electrons ejected in H+-He collisions, with Shore's formula for the resonance 2s2 1S. By extending the observations for this resonance outside the energy range (33 keV to 150 keV), the authors obtain generally a good agreement with the results of other authors.