Symmetrisation effects on the correlation time delay

Abstract

We analyze the electronic correlation contribution to the time delay in the photo-ionization of the excited ortho- and para-Helium states. A simple estimation, based on the ionization probability amplitudes, shows that the different form of anti-symmetrising both states can in principle lead to very different values of the correlation time delay. This result illuminates the interplay between electronic correlations and symmetrisation effects in the attosecond regime, a relation that has been studied in other contexts. Moreover, it suggests the potential of excited states to explore the role of exchange effects in that realm.