A peaking structure in the J/psi phi mass spectrum near threshold is observed in B-+/- -> J/psi phi K-+/- decays, produced in pp collisions at root 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 fb(-1). 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(-11)(+15) (stat.) +/- 19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.
Observation of a peaking structure in the J/psi phi mass spectrum from B-+/- -> J/psi phi K-+/- decays
Sola V.;AMAPANE, Nicola Carlo;ARGIRO', Stefano;CASASSO, STEFANO;COSTA, Marco;MIGLIORE, Ernesto;MONACO, Vincenzo;MUSICH, MARCO;OBERTINO, Maria Margherita;ORTONA, GIACOMO;PELLICCIONI, Mario;POTENZA, ALBERTO;ROMERO, Alessandra;SACCHI, Roberto;SOLANO, Ada Maria;TAMPONI, UMBERTO;BELLAN, Riccardo;COVARELLI, Roberto;
2014-01-01
Abstract
A peaking structure in the J/psi phi mass spectrum near threshold is observed in B-+/- -> J/psi phi K-+/- decays, produced in pp collisions at root 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 fb(-1). 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(-11)(+15) (stat.) +/- 19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.File | Dimensione | Formato | |
---|---|---|---|
PLB734-261.pdf
Accesso aperto
Tipo di file:
PDF EDITORIALE
Dimensione
816.45 kB
Formato
Adobe PDF
|
816.45 kB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.