Diphoton production at hadron colliders and new contact interactions

We explore the capability of the Fermilab Tevatron and CERN LHC to place limits on the possible existence of flavor-independent qq¯γγ contact interactions which can lead to an excess of diphoton events with large invariant masses. Assuming no departure from the standard model is observed, we show that the Tevatron will eventually be able to place a lower bound of 0.5–0.6 TeV on the scale associated with this new contact interaction. At the LHC, scales as large as 3–6 TeV may be probed with suitable detector cuts and an integrated luminosity of 100 ${\mathrm{fb}}^{\mathrm{-}1}$.