Vibrationally resolved photoelectron angular distributions for H2 in the range 17 eV

Abstract

Vibrationally resolved photoelectron angular distributions have been measured for photoionization of ${\mathrm{H}}_{2}$ over the range 17 eV\ensuremath{\le}h\ensuremath{\nu}\ensuremath{\le}39 eV using independent instrumentation at two synchro- tron radiation facilities. The present data greatly extend and add vibrational resolution to earlier variable-wavelength measurements. The average magnitude of the asymmetry parameter continues to lie lower than the best independent-electron calculations. Broad structure is observed for the first time, possibly indicating the effects of channel interaction with dissociative, doubly excited states of ${\mathrm{H}}_{2}$. Neither the average magnitude nor the gross wavelength-dependent structure vary strongly with the final vibrational channel.