title: Violation of the Franck-Condon principle due to recoil effects in high energy molecular core-level photoionization.
abstract: Carbon 1s photoelectron spectra of methane are measured over a photon energy range between 480 eV and 1200 eV. Additional components appear between the individual symmetric stretching vibrational components and are attributed to the excitations of asymmetric stretching and bending vibrations due to recoil of the high-energy photoelectron emission. This recoil effect is the evidence for the violation of the Franck-Condon principle which states that neither the positions nor the momenta of the nuclei change during the ionization event.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan. edwin.kukk@utu.fi
authors.forename: E
authors.initials: E
authors.lastname: Kukk
authors.forename: K
authors.initials: K
authors.lastname: Ueda
authors.forename: U
authors.initials: U
authors.lastname: Hergenhahn
authors.forename: X-J
authors.initials: XJ
authors.lastname: Liu
authors.forename: G
authors.initials: G
authors.lastname: Prümper
authors.forename: H
authors.initials: H
authors.lastname: Yoshida
authors.forename: Y
authors.initials: Y
authors.lastname: Tamenori
authors.forename: C
authors.initials: C
authors.lastname: Makochekanwa
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Kitajima
authors.forename: H
authors.initials: H
authors.lastname: Tanaka