We have measured resonant-Auger decay following Cl 1s−1 excitations in HCl and
CH3Cl molecules, and extracted the pseudo-cross sections of different Cl 2p−2
final states. These cross sections show clear evidence of shake processes as
well as contributions of electronic state-lifetime interference (ELI). To
describe the spectra we developed a fit approach that takes into account ELI
contributions and ultrafast nuclear dynamics in dissociative core-excited
states. Using this approach we utilized the ELI contributions to obtain the
intensity ratios of the overlapping states Cl 1s−14pπ/1s−14pσ in HCl and Cl
1s−14pe/1s−14pa1 in CH3Cl. The experimental value for HCl is compared with
theoretical results showing satisfactory agreement
