Diffractive gamma gamma production at hadron colliders

We compute the cross section for exclusive double-diffractive gammagamma production at the Tevatron, p (p) over bar --> p + gammagamma + (p) over bar, and the LHC. We evaluate both the gg and q (q) over bar t-channel exchange contributions to the process. The observation of exclusive gammagamma production at the Tevatron will provide a check on the model predictions and offer an opportunity to confirm the expectations for exclusive double-diffractive Higgs production at the LHC.