Search for exclusive Z boson production and observation of high mass ppbar->gammagamma->p+ll+pbar events in ppbar collisions at sqrt(s) = 1.96 TeV

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We present a search for exclusive Z boson production in proton-antiproton collisions at sqrt(s) = 1.96 TeV, using the CDF II detector at Fermilab.

• We observe no exclusive Z->ll candidates and place the first upper limit on the exclusive Z cross section in hadron collisions, sigma(exclu) < 0.96 pb at 95% confidence level.
• In addition, we observe eight candidate exclusive dilepton events from the quantum electrodynamic process ppbar->gammagamma->p+ll+pbar, and measure the cross section for M(ll) > 40 GeV/c2 and |eta(l)| < 4 to be sigma = 0.24^{+0.13}_{-0.10} pb, which is the first measurement for this mass range and is consistent with the standard model prediction.