  Ultra-peripheral collisions (UPCs) have been a significant source of study at
RHIC and the LHC. In these collisions, the two colliding nuclei interact
electromagnetically, via two-photon or photonuclear interactions, but not
hadronically; they effectively miss each other. Photonuclear interactions
produce vector meson states or more general photonuclear final states, while
two-photon interactions can produce lepton or meson pairs, or single mesons. In
these interactions, the collision geometry plays a major role. We present a
program, STARlight, that calculates the cross-sections for a variety of UPC
final states and also creates, via Monte Carlo simulation, events for use in
determining detector efficiency.
