To disentangle strong resonant Auger decay lines after the ${\rm{O}}1{\rm{s}}\to 3{\sigma }_{u}^{* }$excitation in O2 molecules

Atomic features may appear in the Auger electron spectra after an electron is excited from a core orbital to an antibonding orbital in molecules, as a result of complex competitions among electron and nuclear motions. Relatively weak atomic features were widely discussed in spectator Auger decay processes on top of excitation in O2 molecules. Thee strong Auger decay processes are heavily-overlapped in the electron spectrum and not discussed up to now. Here, using multi-particle coincidence setup, we separate these Auger decay processes for the first time.