Search for heavy pointlike Dirac monopoles

We have searched for central production of a pair of photons with high transverse energies in p{bar p} collisions at {radical}(s)=1.8 TeV using 70 pb{sup {minus}1} of data collected with the D0 detector at the Fermilab Tevatron in 1994{endash}1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95{percent} C.L. limits of 610, 870, or 1580 GeV/c{sup 2} on the mass of a spin 0, 1/2 , or 1 Dirac monopole. {copyright} {ital 1998} {ital The American Physical Society}