Strong Optical Polarization Effects in Radiation from Low-EnergyNa+-Ne Collisions

Strong polarization effects have been observed in optical radiation from excited $J\ne 0$ states arising from low-energy ${\mathrm{Na}}^{+}$ -Ne collisions. In one case where radiation originates from a $J=1\mathrm{}$ to $J=0\mathrm{}$ transition, oscillations in the excitation function are found to be due exclusively to the polarization component of the radiation perpendicular to the beam direction. These are the first experimental observations of strong sublevel-state selection associated with collisional quantum-mechanical phase-interference phenomena.