Photoproduction of ρ0 in ultra–peripheral nuclear collisions at ALICE
Photoproduction of ρ0 mesons in ultra-peripheral Pb+Pb collisions has been studied by the ALICE Collaboration at the CERN LHC. The strong photon flux associated with relativistic charged nuclei leads to a very large cross section for exclusive photoproduction of ρ0 meson in interactions of the type Pb + Pb → Pb + Pb + ρ0. For a ρ0 produced at mid-rapidity at the LHC, the photon-nucleus center of mass energy is higher than in any previous experiment. The ALICE detector is a general purpose detector dedicated to study heavy-ion collisions. ALICE has excellent performance in the low pT region, and can reconstruct charged particle tracks with 0.1 GeV/c ≤ pT ≤ 100 GeV/c. In this analysis all tracks were required to be within ALICE's central barrel. Analysis of data from the first heavy ion run at the LHC in 2010 will be discussed in this paper.