Ivan Powis, Minna Patanen, Egill Antonsson, Christophe Nicolas, Catalin Miron, and David M. P. Holland (2017) Vibration-dependent photoelectron angular distributions and branching ratios observed across the Cooper-minimum region of bromobenzene, Phys. Rev. A 96, 013413, https://doi.org/10.1103/PhysRevA.96.013413
Vibration-dependent photoelectron angular distributions and branching ratios observed across the Cooper-minimum region of bromobenzene
|Author:||Powis, Ivan1; Patanen, Minna2,3; Antonsson, Egill2,4;|
1School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
2Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
3Current address: Nano and Molecular Systems Research Unit, Molecular Materials Research Community, Faculty of Science, P.O. Box 3000, 90014 University of Oulu, Finland
4Current address: Institut für Chemie und Biochemie - Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
5Current address: Extreme Light Infrastructure-Nuclear Physics (ELI-NP), “Horia Hulubei” National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125 Măgurele, Jud. Ilfov, Romania
6Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD, United Kingdom
|Online Access:||PDF Full Text (PDF, 0.7 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2019092630079
American Physical Society,
|Publish Date:|| 2019-09-26
Vibrational state-resolved photoelectron anisotropy parameters, β, for the ˜X2B1, ˜B2B2, and ˜C2B1 state ionizations of bromobenzene have been recorded at photon energies ranging from 20.5 to 94 eV, thus spanning the region of the expected bromine Cooper minimum (CM). The ˜X state displays no CM and its β value is also independent of vibrational level, in accord with the Franck-Condon approximation. The ˜B and ˜C state β values display the CM to differing degrees, but both show a vibrational dependence that extends to energies well below the obvious CM dip. Calculations are presented that replicate these observations. We thus demonstrate a wide-ranging Franck-Condon approximation breakdown detected in the β anisotropy parameter in the absence of any resonance. Measured and calculated vibrational branching ratios for these states are also presented. Although the ˜B state branching ratios remain constant, in accord with Franck-Condon expectations, the ˜X and (especially) the ˜C state ratios display weak, quasilinear variations across the studied range of photon energy, but with no apparent correlation with the CM position.
Physical review. A
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
114 Physical sciences
This research was funded by the European Community's Seventh Framework Program (FP7/2007-2013) ELISA under Grant Agreement No. 226716. We are grateful to SOLEIL staff for running the facility and providing beam time (Project No. 20120162).
© 2017 American Physical Society.