Systematic effects introduced by neglecting redshift distortions in 2PCF modelling. Left: Residuals from the 2PCF with respect to the full model (i.e. photo-z, RSDs, IR resummation, and geometric distortion correction) for the three cases. The line colours are as follows: the model without RSDs, blue line; model without IR resummation, red line; and model without geometric distortion correction, green line). Shaded areas are given by the square root of the diagonal covariance divided by the number of mocks. Right: Marginalised posterior distributions in the Ω_m–σ₈ plane, with 68% and 95% confidence intervals, from the combination of clustering and weak lensing masses for the three cases represented in the left panel (same colour code) compared to the full redshift effects case (black empty contours). Dotted grey lines are the input cosmology of the catalogues.