The production of J/psi mesons is studied in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 inverse nanobarns. The J/psi differential cross section is determined, as a function of the J/psi transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/psi) component. Integrated over J/psi transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range |y| < 2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9 \pm 2.1 (stat.) \pm 3.0 (syst.) \pm 7.8(luminosity) nb for prompt J/psi mesons assuming unpolarized production and 26.0 \pm 1.4 (stat.) \pm 1.6 (syst.) \pm 2.9 (luminosity) nb for J/psi mesons from b-hadron decays.
CMS Collaboration, Quertenmont, L., Khachatryan, V., Basegmez, S., Bruno, G., Caudron, J., Ceard, L., Cortina Gil, E., de Favereau de Jeneret, J., Delaere, C., Favart, D., Forthomme, L., Giammanco, A., Grégoire, G., Hollar, J., Lemaitre, V., Liao, J., Militaru, O., Nuttens, C., et al. (2011). Prompt and non-prompt J/psi production in pp collisions at sqrt(s) = 7 TeV. European Physical Journal C. Particles and Fields, 71(3), 1575. https://doi.org/10.1140/epjc/s10052-011-1575-8 (Original work published 2011)