Experimental confirmation for resonance enhancement in the electron impact excitation cross sections of the a1Δg and b1Σg+ electronic states of O2

In a recent publication [Phys. Rev. Lett. 68, 2011 (1992)] Noble and Burke applied the R-matrix method to low-energy electron scattering by oxygen molecules. They found that resonant contributions were made to the a1Δg and b1Σg+ scattering cross sections, via a 2Πu resonance, which significantly modified previous theoretical predictions and which were not observed in previous experiments. Here we present new results which provide the first definitive set of experimental data to confirm Noble and Burke's prediction of resonance enhancement in the electron impact excitation of the a and b electronic states