Steric asymmetry in state-resolved NO–Ar collisions

New experimental results are reported on state-dependent steric effects in NO–Ar inelastic scattering. The NO molecules are selected in the J=1/2− Λ-doublet state of the electronic ground state and oriented relative to the incident Ar atoms. The steric asymmetry, S=(σNO−σON)/(σNO+σON), has been measured as a function of the final rotational state J′. In a previous study, quantum-mechanical scattering calculations were found to predict strong oscillations in S, but experimental evidence for this behaviour was not conclusive. The results of experiments presented here provide clear evidence of the qualitative correctness of the theoretical calculations.