Abstract:
We present the first observation of exclusive e+e- production in hadron-hadron collisions, using p[overline p] collision data at sqrt(s)=1.96 TeV taken by the run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532 pb-1. We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy ET>5 GeV and pseudorapidity |eta|<2. With these criteria, 16 events are observed compared to a background expectation of 1.9$\pm$0.3 events. These events are consistent in cross section and properties with the QED process p[overline p]-->p+e+e-+[overline p] through two-photon exchange. The measured cross section is 1.6-0.3+0.5(stat)$\pm$0.3(syst) pb. This agrees with the theoretical prediction of 1.71$\pm$0.01 pb.