title: Anionic photofragmentation of CO: a selective probe of core-level resonances.
abstract: Anion-yield spectroscopy using x rays is shown to be a selective probe of molecular core-level processes, providing unique experimental verification of shape resonances. For CO, partial anion and cation yields are presented for photon energies near the C K edge. The O- yield exhibits features above threshold related only to doubly excited states, in contrast to cation yields which also exhibit pronounced structure due to the well-known sigma* shape resonance. Because the shape resonance is completely suppressed for O-, anion spectroscopy thus constitutes a highly selective probe, yielding information unobtainable with absorption or electron spectroscopy.
authors.affiliation: Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Stolte
authors.forename: D L
authors.initials: DL
authors.lastname: Hansen
authors.forename: M N
authors.initials: MN
authors.lastname: Piancastelli
authors.forename: I
authors.initials: I
authors.lastname: Dominguez Lopez
authors.forename: A
authors.initials: A
authors.lastname: Rizvi
authors.forename: O
authors.initials: O
authors.lastname: Hemmers
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: A S
authors.initials: AS
authors.lastname: Schlachter
authors.forename: M S
authors.initials: MS
authors.lastname: Lubell
authors.forename: D W
authors.initials: DW
authors.lastname: Lindle