Fig. 2
From: Symmetry breakdown of electron emission in extreme ultraviolet photoionization of argon
Results for angular distribution parameters. Experimental (symbols) and theoretical (lines) angular distribution parameters of the neutral Ar ionization (a) and ionization of Ar+ (b). The error for the photon energy is given by the FEL bandwidth and jitter, which lies within the symbol size. The parameter errors are determined by accounting for the noise level of the acquisition hardware as well as including the mean fit error of Eq. (1) for 10 intensity bins per photon energy using all 16 spectrometers
