Experimental and Phenomenological Developments in Ultraperipheral Collisions

We calculate production rates for several hard processes in ultraperipheral proton-nucleus and nucleus-nucleus collisions at the LHC. The resulting high rates demonstrate that some key directions in small x research proposed for HERA will be accessible at the LHC through these ultraperipheral processes. Indeed, these measurements can extend the HERA x range by roughly a factor of 10 for similar virtualities. Nonlinear effects on the parton densities will thus be signiﬁcantly more important in these collisions than at HERA.