Symmetry-selective observation of the N 1s shape resonance in N2

Inner-shell photoelectron :spectra of the N Is level in N-2 have been measured with sufficient resolution to resolve the splitting between the gerade and ungerade components. The selective enhancement of the gerade component on the N-2 sigma shape resonance is clearly seen, confirming that the resonant-behavior is mainly caused by the sigma (u) channel. The splitting of the two components is found to be 97(3) meV.