We present the first observation of exclusive e+ e-
production in hadron-hadron collisions, using p anti-p collision data
at s**(1/2) ñ.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 E(t) >
5 GeV and pseudorapi+dity |eta| < 2. With these criteria, 16 events
are observed compared to a background expectation of 1.9 +/- 0.3 events.
These events are consistent in cross section and properties with the QED
process p anti-p --> p + e+ e- + pbar through two-photon exchange.
The measured cross section is 1.60.5_-0.3(stat) +/- 0.3(syst) pb.
This agrees with the theoretical prediction of 1.71 +/- 0.01 pb.
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Updated: Monday, 2008 November 17 14:21:25 CST automatically from input from carol picciolo