title: Direct probe of the shape resonance mechanism in 2sigma(g)-shell photoionization of the N2 molecule.
abstract: Angular distributions of photoelectrons from a 2sigma(g) shell of fixed-in-space N2 molecules have been measured for left- and right-elliptically polarized and for linearly polarized light at several photon energies in the region of sigma(*) shape resonance. That allowed the determination of a set of dipole matrix elements and phase shift differences characterizing the process. These data clearly show the enhancement of the fsigma(u) partial cross section in the resonance simultaneously with an abrupt increase of the corresponding phase shift by pi, which is the first experimental demonstration of the nature of the sigma(*) shape resonance in homonuclear diatomic molecules.
authors.affiliation: Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Motoki
authors.forename: J
authors.initials: J
authors.lastname: Adachi
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: K
authors.initials: K
authors.lastname: Soejima
authors.forename: A
authors.initials: A
authors.lastname: Yagishita
authors.forename: S K
authors.initials: SK
authors.lastname: Semenov
authors.forename: N A
authors.initials: NA
authors.lastname: Cherepkov