Abellan Beteta, CarlosCalvo Gómez, MíriamCamboni, AlessandroComerma Montells, AlbertDomingo Bonal, FrancescGarrido Beltrán, LluísGrabalosa 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 CollaborationGascón Fora, David2019-05-212019-05-212012-09-260031-9007https://hdl.handle.net/2445/133580The first observation of the decay B 0 → ¯¯¯ D 0 K + K − is reported from an analysis of 0.62     fb − 1 of p p collision data collected with the LHCb detector. Its branching fraction is measured relative to that of the topologically similar decay B 0 → ¯¯¯ D 0 π + π − to be B ( B 0 → ¯¯¯ D 0 K + K − ) B ( B 0 → ¯¯¯ D 0 π + π − ) = 0.056 ± 0.011 ± 0.007 , where the first uncertainty is statistical and the second is systematic. The significance of the signal is 5.8 σ . Evidence, with 3.8 σ significance, for B 0 s → ¯¯¯ D 0 K + K − decays is also presented. The relative branching fraction is measured to be B ( B 0 s → ¯¯¯ D 0 K + K − ) B ( B 0 → ¯¯¯ D 0 K + K − ) = 0.90 ± 0.27 ± 0.20 . These channels are of interest to study the mechanisms behind hadronic B decays, and open new possibilities for C P violation analyses with larger data sets.8 p.application/pdfengcc by (c) CERN; LHCb Collaboration, 2012http://creativecommons.org/licenses/by/3.0/es/Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article6196272019-05-21info:eu-repo/semantics/openAccess