Cross section for the incoherent photoproduction of $\Jpsi$ vector mesons in ultra-peripheral Pb--Pb collisions at $\snn= 5.02$~TeV measured at midrapidity. The uncorrelated uncertainty (statistical and systematic added in quadrature) is indicated with the vertical bar, while the correlated uncertainty by the grey band. The width of each $\mant$ range is given by the horizontal bars. The lines show the predictions of the different models described in the text. The bottom panel presents the ratio of the integral of the predicted to that of the measured cross section in each $\mant$ range. The relative uncertainties on the ratios calculated from GSZ are 45\%.