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Experimental lifetime of the a1Δ electronically excited state of CH−

Gustav Eklund1,*, Moa K. Kristiansson1, K. C. Chartkunchand2, Emma K. Anderson3, Malcolm Simpson4, Roland Wester4, Henning T. Schmidt1,†, Henning Zettergren1, Henrik Cederquist1 et al.

Wolf D. Geppert1

  • 1Department of Physics, Stockholm University, Stockholm 10691, Sweden
  • 2Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
  • 3Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
  • 4Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria

  • *gustav.eklund@fysik.su.se
  • †schmidt@fysik.su.se
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Phys. Rev. Research 4, L012016 – Published 11 February, 2022

DOI: https://doi.org/10.1103/PhysRevResearch.4.L012016

Abstract

By repeatedly probing the a1Δ excited state and the X3Σ− ground-state populations in a beam of CH− ions stored in a cryogenic ion-beam storage ring for 100 s, we extract an intrinsic lifetime of 14.9±0.5 s for this excited state. This is far longer than all earlier experimental and theoretical results, exposing large difficulties in measuring and calculating slow decays and the need for benchmark quality experiments.

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Phys. Rev. Research 4, L012016– Published 11 February, 2022
  • Received 1 November 2021
  • Accepted 24 December 2021
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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