Evidence for shape resonance in theCΣg+2band of CO2+from angle-resolved photoelectron spectroscopy

Abstract

Angle-resolved photoelectron spectra were taken of the fourth band in C${\mathrm{O}}_2$ ($C{}_{}{}^2{}_{}{}^{}{\Sigma }_g_{}^{+}{}_{}{}^{}$) as a function of photon energy using synchrotron radiation. It was found that the value of $\beta$ dropped strongly in the vicinity of the photon energy of 42 eV. This result is shown to be in convincing agreement with theoretical predictions of a shape resonance, particularly when consideration is made of variations in internuclear distance.