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Time-resolved three-body fragmentation of methane in strong laser fields

W. Zhang1,*, D. V. Chicharro1, N. Rapp1, G. Pandey2, M. Kanno3, D. Zhang3, N. Kishimoto3, A. Dorn1, F. Remacle2 et al.

K. Ueda3, T. Pfeifer1,†, and R. Moshammer1,‡

  • *Contact author: weiyu.zhang@mpi-hd.mpg.de
  • †Contact author: t.pfeifer@mpi-hd.mpg.de
  • ‡Contact author: r.moshammer@mpi-hd.mpg.de
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Phys. Rev. Research 8, 033230 – Published 25 August, 2026

DOI: https://doi.org/10.1103/spjb-rq2q

Abstract

Distinct strong-field fragmentation pathways can converge to identical final products in polyatomic molecules, making the underlying reaction dynamics difficult to identify. In methane, Jahn-Teller symmetry breaking after ionization creates distinct intermediate geometries that lead to different three-body routes within the same final fragments. Using delay-dependent, coincidence-resolved momentum correlations in pump-probe Coulomb-explosion imaging, we discriminate fragmentation pathways within the CH2++H++H+ channel. We discover a delay-dependent sequential pathway with a transient H2 fragment, characterized by symmetric proton-proton correlations, and separate it from an asymmetric sequential route and concerted fragmentation. Our results establish that delay-resolved coincidence mapping can disentangle intermediate-mediated fragmentation pathways even within an identical three-body final state, and show that in methane such pathways are seeded by Jahn-Teller-driven symmetry breaking.

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Outline

Information

Phys. Rev. Research 8, 033230– Published 25 August, 2026
  • Received 4 November 2025
  • Revised 24 March 2026
  • Accepted 7 July 2026
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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. Open access publication funded by Max Planck Society.

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