@inproceedings{349828753bac4a66832d410b59548d98,
title = "Studying multielectron excitation and fragmentation with ultrafast XUV-IR spectroscopy",
abstract = "We used XUV-IR transient photoelectron spectroscopy to study excited state dynamics in oxygen and observed 4p excited atomic fragments, which are not an expected dissociation product. This fragment results from previously unexplored multielectron excitation pathway.",
author = "Alexander Plunkett and Nathan Harkema and Lucchese, {Robert R.} and McCurdy, {C. William} and Arvinder Sandhu",
note = "Funding Information: In summary, we find that XUV excitation in the energy range of 23.5 eV to 24 eV generates a significant population of a previously unexplored (4Pg)4p Rydberg state in molecular oxygen. This excitation is unresolved in synchrotron experiments due to its strongly repulsive nature and therefore broad and diffuse absorption spectrum. The fragmentation from this channel has also gone undetected in fluorescence studies because its dissociation products cannot directly fluoresce to the ground state. Furthermore, we show that despite the need for multi-electron excitation, the cross section for the (4Pg)4p state is not negligible, in fact it is comparable to the well-studied (c4Su-) nlsg series. We have demonstrated that ultrafast photoelectron spectroscopy is a tool well suited to study such states, and hetpaplication fohits paproach in other systems can help to identify the role of strongly repulsive multi-electron excitations which usually present a background absorption spectrum in energy domain studies. Extension of our approach to multi-pulse, multi-color pump-probe photoelectron spectroscopy can also shed light on the role of dark states in the charge and energy redistribution mechanisms in molecules. The photoelectron spectroscopy work was supported by the U. S. Army Research Laboratory and the U. S. Army Research Office under grant number W911NF-14-1-0383 and by the National Science Foundation (NSF) award number PHY-1505556. The transient absorption study was supported by the was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Science under award no. DE-SC0018251. Publisher Copyright: {\textcopyright} 2019 The Author(s).; Nonlinear Optics, NLO 2019 ; Conference date: 15-07-2019",
year = "2019",
language = "English (US)",
series = "Optics InfoBase Conference Papers",
publisher = "OSA - The Optical Society",
booktitle = "Nonlinear Optics, NLO 2019",
}