The CMS Collaboration2025-03-072025-03-0720141126-6708https://doi.org/10.1007/JHEP09(2014)094https://hdl.handle.net/20.500.12507/2552Production of prompt J/? 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/? mesons are fully reconstructed via their decays into ? +? -pairs. This observation provides for the first time access to the high-transverse-momentum region of J/? 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/? transverse momentum (p TJ/?) and rapidity (|y J/?|): |y J/?| < 1.2 for p TJ/?> 6.5 GeV/c; 1.2 < |y J/?| < 1.43 for a p Tthreshold that scales linearly with |y J/?| from 6.5 to 4.5 GeV/c; and 1.43 < |y J/?| < 2.2 for p TJ/?> 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from -31% to +27%. [Figure not available: see fulltext.] © 2014 The Author(s).eninfo:eu-repo/semantics/openAccessB physicsKeywords: Hadron-Hadron ScatteringArticle201492-s2.0-8490723248810.1007/JHEP09(2014)094Q1