Circular Dichroism in Photoelectron Angular Distributions from Oriented Linear Molecules

We show that circular dichroism exists in the photoelectron angular distributions from oriented linear molecules in the electric dipole approximation. Contributions to the dichroism arise solely from interferences between degenerate photoelectron continua with $m$ values differing by ±1. We identify specific photon-propagation, electron-detection configurations where circular dichroism will be observable. Finally, we illustrate the magnitude of this effect through ab initio calculations for photoionization out of the $4\sigma$ orbital of an oriented CO molecule.