We introduce time-resolved multielectron coincidence spectroscopy and apply it to the double Auger-Meitner (AM) emission process following xenon $4d$ photoionization. The photoelectron and AM electron(s) are measured in coincidence by using a magnetic-bottle time-of-flight spectrometer, enabling an unambiguous assignment of the complete cascade pathways involving two AM electron emissions. In the presence of a near-infrared (NIR) laser pulse, the intermediate ${\mathrm{Xe}}^{2+*}$ state embedded in the ${\mathrm{Xe}}^{3+}$ continuum is probed through single NIR photon absorption and the lifetime of this intermediate ${\mathrm{Xe}}^{2+*}$ state is directly obtained as $(109\pm 22)\mathrm{fs}$.

• Received 23 August 2023
• Revised 16 November 2023
• Accepted 24 January 2024

DOI:https://doi.org/10.1103/PhysRevLett.132.083201