Figure 2

J/$\psi$ coherent photoproduction cross section as a function of $\langle N_{\rm part} \rangle$ at forward rapidity in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. The vertical bars are the statistical uncertainties and the uncorrelated systematic uncertainties are represented as boxes. The centrality correlated systematic uncertainties are quoted in the legend. Results are compared with theoretical calculations from Ref. [33] (GG-hs), Ref. [32] (IIM S2 and S3, and GBW S2 and S3) and from Ref. [35] with updated Glauber calculations from Ref. [56] (VDM). The figure shows the integral of the cross section measurement as well as the corresponding theoretical model values in each centrality interval. Note that the most central bin, where only an upper limit is given, is half the size of the other intervals. Therefore, to evaluate the centrality dependence of J/$\psi$ coherent photoproduction, both data and theory have to be multiplied by a factor of two.