High-energy proton-hydrogen-atom excitation multipole moments

Proton-hydrogen-atom excitation angle-integrated multiple moments are calculated within a classical trajectory approximation for the relative proton-proton motion, but with full coupling of basis states centred on both protons. For the excitation channels the authors find that the dipole moment within the n=2 states is very sensitive to final-state interactions between the degenerate excited states. The dipole moment is similar in magnitude to the dipole moment induced in electron-hydrogen excitation but the sign is opposite. In this case the electron is more often on the down-beam side of the target proton. The time rate of change of the dipole moment for excitation to n=2 is similar in magnitude and the same sign (negative) as in electron-hydrogen excitation.