Photonuclear production of vector mesons in ultra-peripheral Pb–Pb collisions at the LHC

Vector mesons are copiously produced in ultra-peripheral nucleus–nucleus collisions. In these collisions, the nuclei are separated by impact parameters larger than the sum of the nuclear radii, and the interaction is mediated by the electromagnetic field. The interaction effectively corresponds to a photonuclear interaction between a photon, generated from the electromagnetic field of one of the nuclei, and the target nucleus. The ALICE Collaboration has previously published results on exclusive J/ψ photoproduction at mid and forward rapidities in Pb–Pb collisions. The cross section for this process is a particularly good measure of the nuclear gluon distribution. In this talk, the latest results on exclusive production of light and heavy vector mesons from ALICE in Pb–Pb collisions will be presented.