Experimental \piMd and \piPd correlation functions. The data are obtained from high-multiplicity pp collisions at $\sqrt{s} = 13$~TeV. The top panel shows the measured \piMd correlation function together with the corresponding fit function (magenta). The brown cross-hatched band represents contributions from the $\Delta$ resonance, the blue band denotes the Coulomb and strong FSI interactions, and the teal diagonally hatched band corresponds to the residual background. The widths of the bands indicate the fit uncertainty. The lower panel depicts, in the same representation, the \piPd correlation function. However, the strong FSI interaction is neglected for this system. The $\chi^2$ per degree of freedom is 14/15 for both correlations.