Dimuon invariant mass distribution for low-multiplicity pp collisions, corresponding to the $N_{\mathrm {trk}}^{\mathrm {corr}}$ interval bin $[1, 8]$ (left) and for high-multiplicity pp collisions, corresponding to the $N_{\mathrm {trk}}^{\mathrm {corr}}$ interval bin $[42, 50]$ (right)..