Charmonium and e+e- pair photoproduction in ultra peripheral Pb-Pb collisions at \sqrt s_{NN} = 2.76 TeV

Ultra-relativistic heavy ions generate strong electromagnetic fields which offer the possibility to study  and -nucleus interactions at the LHC in the so called ultra-peripheral collisions(UPC).The J/photoproduction in UPC events is sensitive to the gluon distribution of the interacting nuclei, providing information on the nuclear gluon shadowing at Bjorken-x ranging from 10 -2 to 10 -3 .Here we report on ALICE results of J/ photoproduction measured in Pb-Pb collisions at  s NN = 2.76 TeV where the J/ has been measured in the  decay channel with the ALICE Muon Spectrometer in the rapidity range -3.6<y<-2.6; at midrapidity (|y|<0.9)both the J/ leptonic decay channels (e + e -,  +  -)were used.The cross sections are compared with the predictions provided by several Monte Carlo simulations.In addition the cross section for the e + e -process was studied and compared with the theoretical model expectations.