Measurement of prompt J/Ψ pair production in pp collisions at √s = 7 TeV

Journal Article · Wed Sep 17 04:00:00 UTC 2014 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/JHEP09(2014)094 · OSTI ID:1234835

Khachatryan, Vardan ^[1]

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1. Yerevan Physics Inst. (YerPhI) (Armenia). et al.

Production of prompt J/ψ meson pairs in proton-proton collisions at √s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb^-1. The two J/ψ mesons are fully reconstructed via their decays into μ ⁺ μ ^- pairs. This observation provides for the first time access to the high-transverse-momentum region of J/ψ pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/ψ transverse momentum (p _T ^J/ψ ) and rapidity (|y ^J/ψ |): |y ^J/ψ | < 1.2 for p _T ^J/ψ > 6.5 GeV/c; 1.2 < |y ^J/ψ | < 1.43 for a p _T threshold that scales linearly with |y J/ψ | from 6.5 to 4.5 GeV/c; and 1.43 < |y J/ψ | < 2.2 for p _T ^J/ψ > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/ψ pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/ψ polarization imply modifications to the cross section ranging from -31% to +27%.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• Contributing Organization: CMS Collaboration
• Grant/Contract Number: AC02-07CH11359
• OSTI ID: 1234835
• Report Number(s): FERMILAB-PUB--14-218-CMS; CERN-PH-EP--2014-111; CMS-BPH--11-021; arXiv eprint number arXiv:1406.0484
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 9 Vol. 2014; ISSN 1029-8479
• Publisher: Springer BerlinCopyright Statement
• Country of Publication: United States
• Language: English