Photoproduction in Ultraperipheral Heavy Ion Collisions at RHIC and the LHC

Abstract

This year HERA has shut down- closing a productive period in the study of photon-hadron interactions. It is interesting to compare electron hadron colliders such as HERA with the LHC -particularly in operation with heavy ions where Z 2 α ∼ 1 and Coulomb interactions are clearly significant. Roughly speaking ion collisions at RHIC cover an equivalent energy range to the fixed target tagged photon experiments at Fermilab in the '80's and those at the LHC will extend the energy range of HERA by a factor of 3–10. It is not suprising then that RHIC results have dealt with vector meson production (ρ and J / ψ ). Similarly we can expect the LHC program with heavy ions to probe the structure of the proton to another order of magnitude in x.