Diffractive gamma-gamma production at hadron colliders
  We compute the cross section for exclusive double-diffractive gamma-gamma production at the Tevatron, $p{\bar p} \to p + \gamma\gamma + {\bar p}$, and the LHC. We evaluate both the gluon-gluon and quark-antiquark t-channel exchange contributions to the process. The observation of exclusive gamma-gamma 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. 
V. A. Khoze, A. D. Martin, M. G. Ryskin and W. J. Stirling