Figure 5

Measured differential cross section of J/$\psi$ photoproduction in ultra-peripheral Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}} } = 2.76$ TeV at $-0.9< y< 0.9$ for coherent a) and incoherent b) events. The error is the quadratic sum of the statistical and systematic errors. The theoretical calculations described in the text are also shown.