title: Direct determination of the magnetic quadrupole contribution to the Lyman-α₁ transition in a hydrogenlike ion.
abstract: We report the observation of an interference between the electric dipole (E1) and the magnetic quadrupole (M2) amplitudes for the linear polarization of the Ly-α1 (2p3/2→1s1/2) radiation of hydrogenlike uranium. This multipole mixing arises from the coupling of the ion to different multipole components of the radiation field. Our observation indicates a significant depolarization of the Ly-α1 radiation due to the E1-M2 amplitude mixing. It proves that a combined measurement of the linear polarization and of the angular distribution enables a very precise determination of the ratio of the E1 and the M2 transition amplitudes and the corresponding transition rates without any assumptions concerning the population mechanism for the 2p3/2 state.
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Weber
authors.forename: H
authors.initials: H
authors.lastname: Bräuning
authors.forename: A
authors.initials: A
authors.lastname: Surzhykov
authors.forename: C
authors.initials: C
authors.lastname: Brandau
authors.forename: S
authors.initials: S
authors.lastname: Fritzsche
authors.forename: S
authors.initials: S
authors.lastname: Geyer
authors.forename: S
authors.initials: S
authors.lastname: Hagmann
authors.forename: S
authors.initials: S
authors.lastname: Hess
authors.forename: C
authors.initials: C
authors.lastname: Kozhuharov
authors.forename: R
authors.initials: R
authors.lastname: Märtin
authors.forename: N
authors.initials: N
authors.lastname: Petridis
authors.forename: R
authors.initials: R
authors.lastname: Reuschl
authors.forename: U
authors.initials: U
authors.lastname: Spillmann
authors.forename: S
authors.initials: S
authors.lastname: Trotsenko
authors.forename: D F A
authors.initials: DF
authors.lastname: Winters
authors.forename: Th
authors.initials: T
authors.lastname: Stöhlker