title: Photoexcitation of K-shell and L-shell hollow beryllium.
abstract: We have observed K-shell and L-shell hollow beryllium atoms (2s(2)2p3s and 1s3s(2)3p) created by photoexcitation using synchrotron radiation. Resonance shapes were fitted to the Fano profile and the parameters were deduced. A Dirac-Fock calculation was performed to identify the configuration of the peaks and to predict other hollow atomic peaks. The results of the calculation were in good agreement with the experimental data. The comparison of the transition strength has revealed that the three-electron photoexcitation to the 1s3s(2)3p configuration is stronger than the two-electron photoexcitation to the 2s(2)2p3s configuration. This is attributed to the large overlap between the 2s orbital of the ground state (1s(2)2s(2)) with the orbital of the L-shell hollow state (1s3s(2)3p).
authors.affiliation: Department of Quantum Engineering and Systems Science, The University of Tokyo, Tokyo 113-8656, Japan. hasegawa@q.t.u-tokyo.ac.jp
authors.forename: Shuichi
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Fumiko
authors.initials: F
authors.lastname: Yoshida
authors.forename: Leo
authors.initials: L
authors.lastname: Matsuoka
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Koike
authors.forename: Stephan
authors.initials: S
authors.lastname: Fritzsche
authors.forename: Satoshi
authors.initials: S
authors.lastname: Obara
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Azuma
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nagata