corner
corner

Phys. Rev. Lett. 102, 242001 (2009) [7 pages]

Observation of Exclusive Charmonium Production and γγμ+μ- in pp̅ Collisions at s=1.96  TeV

Download: PDF (222 kB) Buy this article Export: BibTeX or EndNote (RIS)

T. Aaltonen et al. CDF Collaboration
Show All Authors/Affiliations

Received 16 February 2009; published 15 June 2009

See accompanying Physics Focus

In CDF we have observed the reactions p+p̅ →p+X+p̅ , with X being a centrally produced J/ψ, ψ(2S), or χc0, and γγμ+μ- in pp̅ collisions at 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, γ+pJ/ψ(ψ(2S))+p, observed here for the first time in hadron-hadron collisions. We also observe exclusive χc0J/ψ+γ. The cross sections dσ/dy|y=0 for J/ψ, ψ(2S), and χc0 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/ψ production.

© 2009 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.102.242001
DOI:
10.1103/PhysRevLett.102.242001
PACS:
13.85.Fb, 12.38.Qk, 12.40.Vv, 13.60.−r