Fig. 3: Comparison experiment-theory of the photoionisation time delays.

a Experimental (red circles and lines) difference of the photoionisation time delays τ = τ_B − τ_Ar measured in coincidence with \({{{{\rm{CO}}}}}_{2}^{+}\) and Ar⁺ integrated over the photoelectron emission angle (0° − 90°). The error bars (one standard deviation) were derived from fitting the periodic oscillations of the photoelectron spectra using Eq. (1). Same difference of the photoionisation time delays τ extracted from the theoretical models using the static exchange approach (green dashed line), the full model without coupling in the ionic states (blue dashed-dotted line), and the full model including the ionic coupling (black solid line). b Experimental and simulated difference of photoionisation time delays τ for different integration angles in the laboratory frame: (0° − 90°) (black line for theory, red circles and line for experiment), (0° − 50°) (purple dashed-dotted line for theory, blue squares and line for experiment), and (0° − 20°) (orange dashed line for theory, green triangles and line for experiment). Here, all theoretical lines correspond to the full model. The structures visible in the simulated RABBIT delays τ in the energy range  ≈ 25–27 eV are due to the Ar^*(3s¹3p⁶4p¹) and Ar^*(3s¹3p⁶4s¹) resonances in argon.