Resonant dissociative photoionization of H₂ and D₂

We present a theoretical study of dissociative photoionization of H₂ and D₂, with emphasis on resonant effects through intermediate doubly excited states. The theory coherently includes competition between the different dissociation and ionization channels, and makes use of B-spline functions to represent both the electronic and nuclear motions. We show that strong interference effects between resonant and nonresonant amplitudes are responsible for unidentified peaks observed in recent experimenal works, and that, for photon energies smaller than 28 eV, the various peaks can be explained in terms of a single ¹Σ_u⁺ doubly excited state.