Abellan Beteta, CarlosCalvo Gómez, MíriamCamboni, AlessandroComerma Montells, AlbertDomingo Bonal, FrancescGarrido Beltrán, LluísGascón Fora, DavidGrabalosa Gándara, MarcGraciani Díaz, RicardoGraugés Pous, EugeniLópez Asamar, EliasPérez-Calero Yzquierdo, AntonioPicatoste Olloqui, EduardoPie Valls, B. (Blai)Potterat, CédricPuig Navarro, AlbertRoselló, M.Ruiz, Hugo (Ruiz Pérez)Vázquez Gómez, RicardVilasis-Cardona, XavierLHCb Collaboration2014-10-022014-10-022012-051126-6708https://hdl.handle.net/2445/57948The production of J/ψ mesons accompanied by open charm, and of pairs of open charm hadrons are observed in pp collisions at a centre-of-mass energy of 7 TeV using an integrated luminosity of 355 pb−1 collected with the LHCb detector. Model independent measurements of absolute cross-sections are given together with ratios to the measured J/ψ and open charm cross-sections. The properties of these events are studied and compared to theoretical predictions.36 p.application/pdfengcc by (c) LHCb Collaboration, 2012http://creativecommons.org/licenses/by/3.0/HadronsTeoria quàntica de campsGravitacióRelativitat (Física)Teoria quànticaHadronsQuantum field theoryGravitationRelativity (Physics)Quantum theoryinfo:eu-repo/semantics/article6196202014-10-02info:eu-repo/semantics/openAccess