LHCb CollaborationAaij, R.Adeva, B.Adinolfi, M.Adrover, C.Affolder, A.Ajaltouni, Z.Albrecht, J.Alessio, F.Alexander, M.Ali, S.Alkhazov, G.Alvarez Cartelle, P.Alves, A. A. Jr.Amato, S.Amerio, S.Amhis, Y.Anderlini, L.Anderson, J.Andreassen, R.Andrews, J. E.Appleby, R. B.Gutierrez, O. AquinesArchilli, F.Artamonov, A.Artuso, M.Aslanides, E.Auriemma, G.Baalouch, M.Bachmann, S.Back, J. J.Baesso, C.Balagura, V.Baldini, W.Barlow, R. J.Barschel, C.Barsuk, S.Barter, W.Bauer, Th.Bay, A.Beddow, J.Bedeschi, F.Bediaga, I.Belogurov, S.Belous, K.Belyaev, I.Ben-Haim, E.Bencivenni, G.Benson, S.Benton, J.Berezhnoy, A.Bernet, R.Bettler, M.-O.Van Beuzekom, M.Bien, A.Bifani, S.Bird, T.Bizzeti, A.Bjornstad, P. M.Blake, T.Blanc, F.Blouw, J.Blusk, S.Bocci, V.Bondar, A.Bondar, N.Bonivento, W.Borghi, S.Borgia, A.Bowcock, T. J. V.Bowen, E.Bozzi, C.Brambach, T.Van Den Brand, J.Bressieux, J.Brett, D.Britsch, M.Britton, T.Brook, N. H.Brown, H.Bursche, A.Busetto, G.Buytaert, J.Cadeddu, S.Callot, O.Calvi, M.Calvo Gomez, M.Camboni, A.Campana, P.Campora Perez, D.Carbone, A.Carboni, G.Cardinale, R.Cardini, A.Carranza-Mejia, H.Carson, L.Carvalho Akiba, K.Casse, G.Cassina, L.Castillo Garcia, L.Cattaneo, M.Cauet, Ch.Cenci, R.Charles, M.Charpentier, Ph.Chen, P.Cheung, S.-F.Chiapolini, N.Chrzaszcz, M.Ciba, K.Cid Vidal, X.Ciezarek, G.Clarke, P. E. L.Clemencic, M.Cliff, H. V.Closier, J.Coca, C.Coco, V.Cogan, J.Cogneras, E.Collins, P.Comerma-Montells, A.Contu, A.Cook, A.Coombes, M.Coquereau, S.Corti, G.Couturier, B.Cowan, G. A.Craik, D. C.Cunliffe, S.Currie, R.D'Ambrosio, C.David, P.David, P. N. Y.Davis, A.De Bonis, I.De Bruyn, K.De Capua, S.De Cian, M.De Miranda, J. M.De Paula, L.De Silva, W.De Simone, P.Decamp, D.Deckenhoff, M.Del Buono, L.Deleage, N.Derkach, D.Deschamps, O.Dettori, F.Di Canto, A.Dijkstra, H.Dogaru, M.Donleavy, S.Dordei, F.Dosil Suarez, A.Dossett, D.Dovbnya, A.Dupertuis, F.Durante, P.Dzhelyadin, R.Dziurda, A.Dzyuba, A.Easo, S.Egede, U.Egorychev, V.Eidelman, S.Van Eijk, D.Eisenhardt, S.Eitschberger, U.Ekelhof, R.Eklund, L.El Rifai, I.Elsasser, Ch.Falabella, A.Faerber, C.Farinelli, C.Farry, S.Ferguson, D.Fernandez Albor, V.Ferreira Rodrigues, F.Ferro-Luzzi, M.Filippov, S.Fiore, M.Fitzpatrick, C.Fontana, M.Fontanelli, F.Forty, R.Francisco, O.Frank, M.Frei, C.Frosini, M.Furfaro, E.Gallas Torreira, A.Galli, D.Gandelman, M.Gandini, P.Gao, Y.Garofoli, J.Garosi, P.Garra Tico, J.Garrido, L.Gaspar, C.Gauld, R.Gersabeck, E.Gersabeck, M.Gershon, T.Ghez, Ph.Gibson, V.Giubega, L.Gligorov, V. V.Goebel, C.Golubkov, D.Golutvin, A.Gomes, A.Gorbounov, P.Gordon, H.Grabalosa Gandara, M.Graciani Diaz, R.Granado Cardoso, L. A.Grauges, E.Graziani, G.Grecu, A.Greening, E.Gregson, S.Griffith, P.Gruenberg, O.Gui, B.Gushchin, E.Guz, Yu.Gys, T.Hadjivasiliou, C.Haefeli, G.Haen, C.Haines, S. C.Hall, S.Hamilton, B.Hampson, T.Hansmann-Menzemer, S.Harnew, N.Harnew, S. T.Harrison, J.Hartmann, T.He, J.Head, T.Heijne, V.Hennessy, K.Henrard, P.Hernando Morata, J. A.Van Herwijnen, E.Hess, M.Hicheur, A.Hicks, E.Hill, D.Hoballah, M.Hombach, C.Hulsbergen, W.Hunt, P.Huse, T.Hussain, N.Hutchcroft, D.Hynds, D.Iakovenko, V.Idzik, M.Ilten, P.Jacobsson, R.Jaeger, A.Jans, E.Jaton, P.Jawahery, A.Jing, F.John, M.Johnson, D.Jones, C. R.Joram, C.Jost, B.Kaballo, M.Kandybei, S.Kanso, W.Karacson, M.Karbach, T. M.Kenyon, I. R.Ketel, T.Khanji, B.Kochebina, O.Komarov, I.Koopman, R. F.Koppenburg, P.Korolev, M.Kozlinskiy, A.Kravchuk, L.Kreplin, K.Kreps, M.Krocker, G.Krokovny, P.Kruse, F.Kucharczyk, M.Kudryavtsev, V.Kurek, K.Kvaratskheliya, T.La Thi, V. N.Lacarrere, D.Lafferty, G.Lai, A.Lambert, D.Lambert, R. W.Lanciotti, E.Lanfranchi, G.Langenbruch, C.Latham, T.Lazzeroni, C.Le Gac, R.Van Leerdam, J.Lees, J.-P.Lefevre, R.Leflat, A.Lefrancois, J.Leo, S.Leroy, O.Lesiak, T.Leverington, B.Li, Y.Gioi, L. LiLiles, M.Lindner, R.Linn, C.Liu, B.Liu, G.Lohn, S.Longstaff, I.Lopes, J. H.Lopez-March, N.Lu, H.Lucchesi, D.Luisier, J.Luo, H.Lupton, O.Machefert, F.Machikhiliyan, I. V.Maciuc, F.Maev, O.Malde, S.Manca, G.Mancinelli, G.Maratas, J.Marconi, U.Marino, P.Maerki, R.Marks, J.Martellotti, G.Martens, A.Martin Sanchez, A.Martinelli, M.Martinez Santos, D.Martins Tostes, D.Martynov, A.Massafferri, A.Matev, R.Mathe, Z.Matteuzzi, C.Maurice, E.Mazurov, A.Mccarthy, J.Mcnab, A.Mcnulty, R.Mcskelly, B.Meadows, B.Meier, F.Meissner, M.Merk, M.Milanes, D. A.Minard, M.-N.Molina Rodriguez, J.Monteil, S.Moran, D.Morawski, P.Morda, A.Morello, M. J.Mountain, R.Mous, I.Muheim, F.Mueller, K.Muresan, R.Muryn, B.Muster, B.Naik, P.Nakada, T.Nandakumar, R.Nasteva, I.Needham, M.Neubert, S.Neufeld, N.Nguyen, A. D.Nguyen, T. D.Nguyen-Mau, C.Nicol, M.Niess, V.Niet, R.Nikitin, N.Nikodem, T.Nomerotski, A.Novoselov, A.Oblakowska-Mucha, A.Obraztsov, V.Oggero, S.Ogilvy, S.Okhrimenko, O.Oldeman, R.Orlandea, M.Otalora Goicochea, J. M.Owen, P.Oyanguren, A.Pal, B. K.Palano, A.Palutan, M.Panman, J.Papanestis, A.Pappagallo, M.Parkes, C.Parkinson, C. J.Passaleva, G.Patel, G. D.Patel, M.Patrick, G. N.Patrignani, C.Pavel-Nicorescu, C.Pazos Alvarez, A.Pearce, A.Pellegrino, A.Penso, G.Pepe Altarelli, M.Perazzini, S.Perez Trigo, E.Perez-Calero Yzquierdo, A.Perret, P.Perrin-Terrin, M.Pescatore, L.Pesen, E.Pessina, G.Petridis, K.Petrolini, A.Phan, A.Picatoste Olloqui, E.Pietrzyk, B.Pilar, T.Pinci, D.Playfer, S.Plo Casasus, M.Polci, F.Polok, G.Poluektov, A.Polycarpo, E.Popov, A.Popov, D.Popovici, B.Potterat, C.Powell, A.Prisciandaro, J.Pritchard, A.Prouve, C.Pugatch, V.Navarro, A. PuigPunzi, G.Qian, W.Rademacker, J. H.Rakotomiaramanana, B.Rangel, M. S.Raniuk, I.Rauschmayr, N.Raven, G.Redford, S.Reid, M. M.Dos Reis, A. C.Ricciardi, S.Richards, A.Rinnert, K.Rives Molina, V.Romero, D. A. RoaRobbe, P.Roberts, D. A.Rodrigues, A. B.Rodrigues, E.Rodriguez Perez, P.Roiser, S.Romanovsky, V.Romero Vidal, A.Rouvinet, J.Ruf, T.Ruffini, F.Ruiz, H.Ruiz Valls, P.Sabatino, G.Saborido Silva, J. J.Sagidova, N.Sail, P.Saitta, B.Salustino Guimaraes, V.Sanmartin Sedes, B.Santacesaria, R.Santamarina Rios, C.Santovetti, E.Sapunov, M.Sarti, A.Satriano, C.Satta, A.Savrie, M.Savrina, D.Schiller, M.Schindler, H.Schlupp, M.Schmelling, M.Schmidt, B.Schneider, O.Schopper, A.Schune, M.-H.Schwemmer, R.Sciascia, B.Sciubba, A.Seco, M.Semennikov, A.Senderowska, K.Sepp, I.Serra, N.Serrano, J.Seyfert, P.Shapkin, M.Shapoval, I.Shatalov, P.Shcheglov, Y.Shears, T.Shekhtman, L.Shevchenko, O.Shevchenko, V.Shires, A.Coutinho, R. SilvaSirendi, M.Skidmore, N.Skwarnicki, T.Smith, N. A.Smith, E.Smith, E.Smith, J.Smith, M.Sokoloff, M. D.Soler, F. J. P.Soomro, F.Souza, D.Souza De Paula, B.Spaan, B.Sparkes, A.Spradlin, P.Stagni, F.Stahl, S.Steinkamp, O.Stevenson, S.Stoica, S.Stone, S.Storaci, B.Straticiuc, M.Straumann, U.Subbiah, V. K.Sun, L.Sutcliffe, W.Swientek, S.Syropoulos, V.Szczekowski, M.Szczypka, P.Szilard, D.Szumlak, T.T'Jampens, S.Teklishyn, M.Teodorescu, E.Teubert, F.Thomas, C.Thomas, E.Van Tilburg, J.Tisserand, V.Tobin, M.Tolk, S.Tonelli, D.Topp-Joergensen, S.Torr, N.Tournefier, E.Tourneur, S.Tran, M. T.Tresch, M.Tsaregorodtsev, A.Tsopelas, P.Tuning, N.Ubeda Garcia, M.Ukleja, A.Ustyuzhanin, A.Uwer, U.Vagnoni, V.Valenti, G.Vallier, A.Gomez, R. VazquezVazquez Regueiro, P.Vazquez Sierra, C.Vecchi, S.Velthuis, J. J.Veltri, M.Veneziano, G.Vesterinen, M.Viaud, B.Vieira, D.Vilasis-Cardona, X.Vollhardt, A.Volyanskyy, D.Voong, D.Vorobyev, A.Vorobyev, V.Voss, C.Voss, H.Waldi, R.Wallace, C.Wallace, R.Wandernoth, S.Wang, J.Ward, D. R.Watson, N. K.Webber, A. D.Websdale, D.Whitehead, M.Wicht, J.Wiechczynski, J.Wiedner, D.Wiggers, L.Wilkinson, G.Williams, M. P.Williams, M.Wilson, F. F.Wimberley, J.Wishahi, J.Wislicki, W.Witek, M.Wotton, S. A.Wright, S.Wu, S.Wyllie, K.Xie, Y.Xing, Z.Yang, Z.Yuan, X.Yushchenko, O.Zangoli, M.Zavertyaev, M.Zhang, F.Zhang, L.Zhang, W. C.Zhang, Y.Zhelezov, A.Zhokhov, A.Zhong, L.Zvyagin, A.2013-12-092013-12-092013-12-09201310.1103/PhysRevD.88.072005https://infoscience.epfl.ch/handle/20.500.14299/97720WOS:000326042500002The first observation of the (B) over bar (0) -> J/psi K+K- decay is presented with a data sample corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions at a center-of-mass energy of 7 TeV collected with the LHCb detector. The branching fraction is measured to be B((B) over bar (0) -> J/psi K+K-) = (2.53 +/- 0.31 +/- 0.19) x 10(-6), where the first uncertainty is statistical and the second is systematic. An amplitude analysis of the final state in the (B) over bar (0) -> J/psi K+K- decay is performed to separate resonant and nonresonant contributions in the K+K- spectrum. Evidence of the a(0)(980) resonance is reported with statistical significance of 3.9 standard deviations. The corresponding product branching fraction is measured to be B((B) over bar (0) -> J/psi a(0)(980), a(0)(980) -> K+K-) = (4.70 +/- 3.31 +/- 0.72) x 10(-7), yielding an upper limit of B((B) over bar (0) -> J/psi a(0)(980), a(0)(980) -> K+K-) < 9.0 x 10(-7) at 90% confidence level. No evidence of the resonant decay <(B)over bar>(0) J/psi phi is found, and an upper limit on its branching fraction is set to be B((B) over bar (0) -> J/psi phi) <1.9 x 10(-7) at 90% confidence level.text::journal::journal article::research article