HE EXCITATION IN COLLISIONS WITH PROTONS - AN UNRESOLVED PROBLEM

We Point out an inconsistency in the published information on He excitation in H+-He collisions. While renormalization of experimental data at higher energies results in mutual agreement of the data among themselves and with results of the Born approximation, published information on excitation to 2 1P and 2 1S states is at variance with excitation cross sections to higher n 1L states. As a tentative solution, we present a calculation of n 1P excitation, n = 2-4, within a one-electron close-coupling model.