Angular distribution of electronic decay following molecular and Rydberg excitations at the Cl2pedge of HCl

Abstract

Angle-resolved Auger electron spectra have been measured at the Cl ${2p}_{3/2}$ to ${\ensuremath{\sigma}}^{*}$ and $4s\ensuremath{\sigma}$ resonances of the HCl molecule. The ${2p}_{3/2}^{\ensuremath{-}1}{\ensuremath{\sigma}}^{*}$ state can dissociate before electronic deexcitation, resulting in Auger decay in the core-excited chlorine atom. The asymmetry parameters ${\ensuremath{\alpha}}_{2}$ of these atomic decay lines are similar to those of the normal Auger transitions in isoelectronic Ar. The molecular decay features at both the HCl resonances also show anisotropy which is different in each case despite the states of the same symmetry. Their angular distribution appears to have no correlation with the spectra of argon.