2026-04-13T06:46:29Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1333262025-12-05T16:51:07Zcom_2072_1057col_2072_478823col_2072_478904col_2072_478917

00925njm 22002777a 4500 dc Calvo Gómez, Míriam author Camboni, Alessandro author Comerma Montells, Albert author Garrido Beltrán, Lluís author Graciani Díaz, Ricardo author Graugés Pous, Eugeni author Oyanguren Campos, Arantza de author Pérez-Calero Yzquierdo, Antonio author Picatoste Olloqui, Eduardo author Potterat, Cédric author Rives Molina, Vicente José author Ruiz, Hugo (Ruiz Pérez) author Ruiz Valls, Pablo author Vilasis-Cardona, Xavier author LHCb Collaboration author 2019-05-16T14:45:58Z 2019-05-16T14:45:58Z 2013-09-10 2019-05-16T14:45:58Z A broad peaking structure is observed in the dimuon spectrum of B + → K + μ + μ − decays in the kinematic region where the kaon has a low recoil against the dimuon system. The structure is consistent with interference between the B + → K + μ + μ − decay and a resonance and has a statistical significance exceeding six standard deviations. The mean and width of the resonance are measured to be 4191 + 9 − 8     MeV / c 2 and 65 + 22 − 16     MeV / c 2 , respectively, where the uncertainties include statistical and systematic contributions. These measurements are compatible with the properties of the ψ ( 4160 ) meson. First observations of both the decay B + → ψ ( 4160 ) K + and the subsequent decay ψ ( 4160 ) → μ + μ − are reported. The resonant decay and the interference contribution make up 20% of the yield for dimuon masses above 3770     MeV / c 2 . This contribution is larger than theoretical estimates. Física de partícules Experiments Particle physics Experiments Observation of a Resonance in B+→K+μ+μ− Decays at Low Recoil