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 Collaboration2019-04-082019-04-082012-09-011550-7998https://hdl.handle.net/2445/131785The decay ¯¯¯ B 0 s → J / ψ π + π − can be exploited to study C P violation. A detailed understanding of its structure is imperative in order to optimize its usefulness. An analysis of this three-body final state is performed using a 1.0     fb − 1 sample of data produced in 7 TeV p p collisions at the LHC and collected by the LHCb experiment. A modified Dalitz plot analysis of the final state is performed using both the invariant mass spectra and the decay angular distributions. The π + π − system is shown to be dominantly in an S -wave state, and the C P -odd fraction in this ¯¯¯ B 0 s decay is shown to be greater than 0.977 at 95% confidence level. In addition, we report the first measurement of the J / ψ π + π − branching fraction relative to J / ψ ϕ of ( 19.79 ± 0.47 ± 0.52 ) % .20 p.application/pdfengcc by (c) CERN; LHCb Collaboration, 2012http://creativecommons.org/licenses/by/3.0/es/Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article6196142019-04-08info:eu-repo/semantics/openAccess