Reevaluation of the use of photoelectron angular distributions as a probe of dynamical processes: Strong dependence of such distributions from [formula presented] paradifluorobenzene on photoelectron kinetic energy

Abstract

Photoelectron angular distributions (PADs) have been measured following the excitation of the [Formula presented] origin band in paradifluorobenzene using a range of ionizing wavelengths and for resolved ion vibrational states. The PADs show a dramatic sensitivity to the photoelectron kinetic energy over an energy range of at least 1 eV from threshold, and almost no sensitivity to any prepared intermediate state alignment. This has important consequences for those studies of intramolecular dynamics that use PADs. We suggest that the observed behavior is caused by a shape resonance in the continuum. © 2003 The American Physical Society.