Resonant multiphoton ionization via the Fano autoionization formalism

Abstract
We introduce an analogy between the theory of autoionizing states as described by Fano and the theory of certain states ("pseudo-autoionizing states") of an irradiated atom. These "pseudo-autoionizing states" are used to obtain a number of qualitative results concerning resonant multiphoton ionization probabilities for several experimental arrangements. This method makes clear the importance of nonresonant processes in determining resonant multiphoton ionization line shapes.