title: Radiative and relativistic effects in the decay of highly excited states in helium
abstract: A recent experimental study [J.-E. Rubensson et al., Phys. Rev. Lett. 83, 947 (1999)] measured a significant fluorescence yield of the He( 2lnl(')) photoexcited resonances, showing major qualitative differences from nonrelativistic predictions. We present a further theoretical study of these states, and perform R-matrix multichannel quantum defect theory calculations to extract fluorescence and ionization cross sections. These theoretical results are in excellent agreement with newer, higher-resolution measurements. Radiative and spin-orbit effects are quantified and shown to play an important role in the overall characterization of highly excited states.
authors.affiliation: Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5151, USA.
authors.initials: TW
authors.lastname: Gorczyca
authors.initials: JE
authors.lastname: Rubensson
authors.initials: C
authors.lastname: Sathe
authors.initials: M
authors.lastname: Strom
authors.initials: M
authors.lastname: Agaker
authors.initials: D
authors.lastname: Ding
authors.initials: S
authors.lastname: Stranges
authors.initials: R
authors.lastname: Richter
authors.initials: M
authors.lastname: Alagia