Photoproduction of vector mesons in ultra-peripheral Pb-Pb interactions with ALICE

Abstract

Cross section measurements for vector meson production in ultra-peripheral collisions provide important insight into nuclear gluon distributions, the production mechanisms of vector mesons and a better understanding of the early stages of heavy ion collisions. With data collected during LHC \mbox{Run 1}, \mbox{ALICE} measured vector meson production in ultra-peripheral Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV.  Detector upgrades and improved triggers before LHC \mbox{Run 2} will be discussed. These improvements have allowed a much higher statistics data set to be collected for ultra-peripheral collisions at $\sqrt{s_{NN}}=5.02$ TeV.  The new data allow for more differential studies to be performed and to probe nuclear gluon distributions at lower values of Bjorken $x$. The most recent \mbox{ALICE} measurements of vector meson production for $\rho^{0}$, J/$\psi$, and $\psi$(2S) mesons will be presented along with comparisons to the latest available models.