Polarized-Photon, Scattered-Atom Coincidence Measurements inHe+-He Collisions

Photon-scattered-atom coincidence measurements with polarization analysis of the photons have been made for 3.0-keV ${\mathrm{He}}^{+}$ -He collisions leading to He ($3{}_{}{}^3{}_{}{}^{}P$) excitation in a charge-transfer process. The phase difference between the scattering amplitudes for $m_l=0\mathrm{}$ and $m_l=1\mathrm{}$ magnetic sublevel formation is an approximately constant function of scattering angle. We propose a theory which predicts the constancy of this phase difference.