Coherent ρ0 photoproduction in ultra-peripheral Pb-Pb collisions at sNN=2.76 TeV

We report the first measurement at the LHC of coherent photoproduction ofρ0mesons in ultra- peripheral Pb-Pb collisions. The invariant mass and transverse momentumdistributions forρ0production are studied in theπ+π−decay channel at mid-rapidity.The production cross section in the rapidity range|y|<0.5 is found to be dσ/dy= 425±10 (stat.)+42−50(sys.) mb. Coherentρ0production is studied with and without requirementof nuclear breakup, and the fractional yields for various breakup scenarios are presented.The results are compared with those from lower energies and with model predictions