Garrido Beltrán, LluísGraciani Díaz, RicardoGraugés Pous, EugeniMarin Benito, CarlaPicatoste Olloqui, EduardoRives Molina, Vicente JoséRuiz, Hugo (Ruiz Pérez)LHCb Collaboration2022-05-172022-05-172014-071126-6708https://hdl.handle.net/2445/185659Decays of the form B0 (s) → J/ψ K0 S h +h (′)− (h (′) = K, π) are searched for in protonproton collision data corresponding to an integrated luminosity of 1.0 fb−1 recorded with the LHCb detector. The first observation of the B0 s → J/ψ K0 SK±π ∓ decay is reported, with significance in excess of 10 standard deviations. The B0 → J/ψ K0 SK+K− decay is also observed for the first time. The branching fraction of B0 → J/ψ K0 S π +π − is determined, to significantly better precision than previous measurements, using B0 → J/ψ K0 S as a normalisation channel. Branching fractions and upper limits of the other B0 (s) → J/ψ K0 S h +h (′)− modes are determined relative to that of the B0 → J/ψ K0 S π +π − decay.31 p.application/pdfengcc-by (c) Garrido Beltrán, Lluis et al., 2014https://creativecommons.org/licenses/by/4.0/HadronsGran Col·lisionador d'HadronsFísica de partículesExperimentsHadronsLarge Hadron Collider (France and Switzerland)Particle physicsExperimentsinfo:eu-repo/semantics/article6492122022-05-17info:eu-repo/semantics/openAccess