Observation of Exclusive Gamma Gamma Production in $p \bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

We have observed exclusive {gamma} production in proton-antiproton collisions at {radical}s = 1.96 TeV, using data from 1.11 {+-} 0.07 fb{sup -1} integrated luminosity taken by the Run II Collider Detector at Fermilab. We selected events with two electromagnetic showers, each with transverse energy E{sub T} > 2.5 GeV and pseudorapidity |{eta}| < 1.0, with no other particles detected in -7.4 < {eta} < +7.4. The two showers have similar E{sub T} and azimuthal angle separation {Delta}{phi} {approx} {pi}; 34 events have two charged particle tracks, consistent with the QED process p{bar p} {yields} p + e{sup +}e{sup -} + {bar p} by two-photon exchange, while 43 events have no charged tracks. The number of these events that are exclusive {pi}{sup 0}{pi}{sup 0} is consistent with zero and is < 15 at 95% C.L. The cross section for p{bar p} {yields} p + {gamma}{gamma} + {bar p} with |{eta}({gamma})| < 1.0 and E{sub T} ({gamma}) > 2.5 GeV is 2.48{sub -0.35}{sup +0.40}(stat){sub -0.51}{sup +0.40}(syst)pb