Observation of Exclusive Charmonium Production and γγ → μ+μ- in p(p)over-bar Collisions at √s=1.96 TeV

In CDF we have observed the reactions p + (p) over bar -> p + X + (p) over bar, with X being a centrally produced J/psi, psi(2S), or chi(c0), and gamma gamma -> mu(+)mu(-) in p (p) over bar collisions at root s = 1.96 TeV. The event signature requires two oppositely charged central muons, and either no other particles or one additional photon detected. Exclusive vector meson production is as expected for elastic photoproduction, gamma + p -> J/psi(psi(2S)) + p, observed here for the first time in hadron-hadron collisions. We also observe exclusive chi(c0) -> J/psi + gamma. The cross sections d sigma/dy vertical bar(y=0) for J/psi, psi(2S), and chi(c0) are 3.92 +/- 0: 25(stat) +/- 0.52(syst) nb, 0.53 +/- 0.09(stat) +/- 0.10(syst) nb, and 76 +/- 10(stat) +/- 10(syst) nb, respectively, and the continuum is consistent with QED. We put an upper limit on the cross section for Odderon exchange in exclusive J/psi production.