title: Spectral identification of diffuse resonances in H2 above the n = 2 dissociation limit.
abstract: The resonance structure in molecular hydrogen above the n = 2 dissociation limit is experimentally investigated in a 1 XUV + 1 VIS coherent two-step laser excitation process, with subsequent ionization of H(n = 2) products. Diffuse spectral features exhibiting widths of several cm(-1) in the excitation range of 118,500-120,500 cm(-1) are probed. Information on angular momentum selection rules for parallel and crossed polarizations, combination differences, the para-ortho distinction, extrapolation from rovibrational structure in the bound region below the n = 2 threshold, and mass-selective detection of H(2)(+) parent and H(+) daughter fragments is used as input. This allows for an assignment of the diffuse resonances observed in terms of (1)Σ(g)(+), (1)Π(g), and (1)Δ(g) states, specified with vibrational and rotational quantum numbers.
authors.affiliation: Institute for Lasers, Life and BioPhotonics, VU University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
authors.forename: T I
authors.initials: TI
authors.lastname: Ivanov
authors.forename: C A
authors.initials: CA
authors.lastname: de Lange
authors.forename: W
authors.initials: W
authors.lastname: Ubachs