Observation of a peaking structure in the $J/\psi \phi$ mass spectrum from $B^{\pm} \to J/\psi \phi K^{\pm}$ decays

CMS collaboration (2210 authors)Hollar, JonathanNayak, ArunaCalpas, BettyAlmeida, NunoBargassa, PedrameDavid Tinoco Mendes, AndreFaccioli, PietroFerreira Parracho, Pedro GuilhermeGallinaro, MicheleRodrigues Antunes, JoaoSeixas, JoaoVarela, JoaoVischia, PietroLloret Iglesias, LaraMusella, PasqualeSilva, PedroPela, JoaoLeonardo, Nuno2019-02-032019-02-032014-06-27http://dx.doi.org/10.1016/j.physletb.2014.05.055http://hdl.handle.net/10400.26/26477A peaking structure in the J/psi phi mass spectrum near threshold is observed in B(+/-) to J/psi phi K(+/-) decays, produced in pp collisions at sqrt(s) = 7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/psi, corresponds to an integrated luminosity of 5.2 inverse femtobarns. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m = 4148.0 +- 2.4 (stat.) +- 6.3 (syst.) MeV and Gamma = 28 +15 -11 (stat.) +- 19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.engObservation of a peaking structure in the $J/\psi \phi$ mass spectrum from $B^{\pm} \to J/\psi \phi K^{\pm}$ decaysjournal article2019-02-03