The LHCb VELO upgrade

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Elsevier BV 636:1 (2011) S185-S193

Authors:

P Collins, K Akiba, M Alexander, M Artuso, F Bayer, MG van Beuzekom, S Blusk, TJV Bowcock, J Buytaert, M Campbell, V Coco, M Crossley, R Dumps, L Eklund, D Esperante, L Ferre Llin, A Gallas, M Gandelman, M Gersabeck, V Gligorov, T Huse, M John, M Kucharczyk, X Llopart, D Maneuski, T Michel, R Mountain, M Nichols, A Papadelis, C Parkes, R Plackett, T Poikela, E Rodrigues, L Tlustos, JC Wang, M Whitehead, Z Xing

Measurement of b hadron lifetimes in exclusive decays containing a J/ψ in pp collisions at √s=1.96 TeV.

Phys Rev Lett 106:12 (2011) 121804

Authors:

T Aaltonen, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, A Apresyan, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, G Bauer, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, KR Bland, C Blocker, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, A Brisuda, C Bromberg, E Brucken, M Bucciantonio, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, S Cabrera, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, A Canepa, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, A Clark, D Clark, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli, C Cuenca Almenar, J Cuevas, R Culbertson, D Dagenhart, N d'Ascenzo, M Datta, P de Barbaro, S De Cecco, G De Lorenzo, M Dell'Orso, C Deluca, L Demortier, J Deng, M Deninno, F Devoto, M d'Errico, A Di Canto, B Di Ruzza, JR Dittmann, M D'Onofrio, S Donati, P Dong, T Dorigo, K Ebina, A Elagin, A Eppig, R Erbacher, D Errede, S Errede, N Ershaidat, R Eusebi, HC Fang, S Farrington, M Feindt, JP Fernandez, C Ferrazza, R Field, G Flanagan, R Forrest, MJ Frank, M Franklin, JC Freeman, I Furic, M Gallinaro, J Galyardt, JE Garcia, AF Garfinkel, P Garosi, H Gerberich, E Gerchtein, S Giagu, V Giakoumopoulou, P Giannetti, K Gibson, CM Ginsburg, N Giokaris, P Giromini, M Giunta, G Giurgiu, V Glagolev, D Glenzinski, M Gold, D Goldin, N Goldschmidt, A Golossanov, G Gomez, G Gomez-Ceballos, M Goncharov, O González, I Gorelov, AT Goshaw, K Goulianos, A Gresele, S Grinstein, C Grosso-Pilcher, RC Group, J Guimaraes da Costa, Z Gunay-Unalan, C Haber, SR Hahn, E Halkiadakis, A Hamaguchi, JY Han, F Happacher, K Hara, D Hare, M Hare, RF Harr, K Hatakeyama, C Hays, M Heck, J Heinrich, M Herndon, S Hewamanage, D Hidas, A Hocker, W Hopkins, D Horn, S Hou, RE Hughes, M Hurwitz, U Husemann, N Hussain, M Hussein, J Huston, G Introzzi, M Iori, A Ivanov, E James, D Jang, B Jayatilaka, EJ Jeon, MK Jha, S Jindariani, W Johnson, M Jones, KK Joo, SY Jun, TR Junk, T Kamon, PE Karchin, Y Kato, W Ketchum, J Keung, V Khotilovich, B Kilminster, DH Kim, HS Kim, HW Kim, JE Kim, MJ Kim, SB Kim, SH Kim, YK Kim, N Kimura, S Klimenko, K Kondo, DJ Kong, J Konigsberg, A Korytov, AV Kotwal, M Kreps, J Kroll, D Krop, N Krumnack, M Kruse, V Krutelyov, T Kuhr, M Kurata, S Kwang, AT Laasanen, L Labarga, S Lami, S Lammel, M Lancaster, RL Lander, K Lannon, A Lath, G Latino, I Lazzizzera, T LeCompte, E Lee, HS Lee, JS Lee, SW Lee, S Leo, S Leone, JD Lewis, C-J Lin, J Linacre, M Lindgren, E Lipeles, A Lister, DO Litvintsev, C Liu, Q Liu, T Liu, S Lockwitz, NS Lockyer, A Loginov, D Lucchesi, J Lueck, P Lujan, P Lukens, G Lungu, J Lys, R Lysak, R Madrak, K Maeshima, K Makhoul, P Maksimovic, S Malde, S Malik, G Manca, A Manousakis-Katsikakis, F Margaroli, C Marino, M Martínez, R Martínez-Ballarín, P Mastrandrea, M Mathis, ME Mattson, P Mazzanti, KS McFarland, P McIntyre, R McNulty, A Mehta, P Mehtala, A Menzione, C Mesropian, T Miao, D Mietlicki, A Mitra, H Miyake, S Moed, N Moggi, MN Mondragon, CS Moon, R Moore, MJ Morello, J Morlock, P Movilla Fernandez, A Mukherjee, Th Muller, P Murat, M Mussini, J Nachtman, Y Nagai, J Naganoma, I Nakano, A Napier, J Nett, C Neu, MS Neubauer, J Nielsen, L Nodulman, O Norniella, E Nurse, L Oakes, SH Oh, YD Oh, I Oksuzian, T Okusawa, R Orava, L Ortolan, S Pagan Griso, C Pagliarone, E Palencia, V Papadimitriou, AA Paramonov, J Patrick, G Pauletta, M Paulini, C Paus, DE Pellett, A Penzo, TJ Phillips, G Piacentino, E Pianori, J Pilot, K Pitts, C Plager, L Pondrom, K Potamianos, O Poukhov, F Prokoshin, A Pronko, F Ptohos, E Pueschel, G Punzi, J Pursley, A Rahaman, V Ramakrishnan, N Ranjan, I Redondo, P Renton, M Rescigno, F Rimondi, L Ristori, A Robson, T Rodrigo, T Rodriguez, E Rogers, S Rolli, R Roser, M Rossi, F Ruffini, A Ruiz, J Russ, V Rusu, A Safonov, WK Sakumoto, L Santi, L Sartori, K Sato, V Saveliev, A Savoy-Navarro, P Schlabach, A Schmidt, EE Schmidt, MP Schmidt, M Schmitt, T Schwarz, L Scodellaro, A Scribano, F Scuri, A Sedov, S Seidel, Y Seiya, A Semenov, F Sforza, A Sfyrla, SZ Shalhout, T Shears, PF Shepard, M Shimojima, S Shiraishi, M Shochet, I Shreyber, A Simonenko, P Sinervo, A Sissakian, K Sliwa, JR Smith, FD Snider, A Soha, S Somalwar, V Sorin, P Squillacioti, M Stanitzki, R St Denis, B Stelzer, O Stelzer-Chilton, D Stentz, J Strologas, GL Strycker, Y Sudo, A Sukhanov, I Suslov, K Takemasa, Y Takeuchi, J Tang, M Tecchio, PK Teng, J Thom, J Thome, GA Thompson, E Thomson, P Ttito-Guzmán, S Tkaczyk, D Toback, S Tokar, K Tollefson, T Tomura, D Tonelli, S Torre, D Torretta, P Totaro, M Trovato, Y Tu, N Turini, F Ukegawa, S Uozumi, A Varganov, E Vataga, F Vázquez, G Velev, C Vellidis, M Vidal, I Vila, R Vilar, M Vogel, G Volpi, P Wagner, RL Wagner, T Wakisaka, R Wallny, SM Wang, A Warburton, D Waters, M Weinberger, H Wenzel, WC Wester, B Whitehouse, D Whiteson, AB Wicklund, E Wicklund, S Wilbur, F Wick, HH Williams, JS Wilson, P Wilson, BL Winer, P Wittich, S Wolbers, H Wolfe, T Wright, X Wu, Z Wu, K Yamamoto, J Yamaoka, T Yang, UK Yang, YC Yang, W-M Yao, GP Yeh, K Yi, J Yoh, K Yorita, T Yoshida, GB Yu, I Yu, SS Yu, JC Yun, A Zanetti, Y Zeng, S Zucchelli, CDF Collaboration

Abstract:

We report on a measurement of b-hadron lifetimes in the fully reconstructed decay modes B(+)→J/ψK(+), B⁰→J/ψK*(892)⁰, B⁰→J/ψK(s)⁰, and Λ(b)⁰→J/ψΛ⁰ using data corresponding to an integrated luminosity of 4.3 fb⁻¹, collected by the CDF II detector at the Fermilab Tevatron. The measured lifetimes are τ(B(+))=[1.639±0.009(stat)±0.009(syst)] ps, τ(B⁰)=[1.507±0.010(stat)±0.008(syst)] ps, and τ(Λ(b)⁰)=[1.537±0.045(stat)±0.014(syst)] ps. The lifetime ratios are τ(B(+))/τ(B⁰)=[1.088±0.009(stat)±0.004(syst)] and τ(Λ(b)⁰)/τ(B⁰)=[1.020±0.030(stat)±0.008(syst)]. These are the most precise determinations of these quantities from a single experiment.

Measurement of b hadron lifetimes in exclusive decays containing a J/ψ in pp̄ collisions at √s=1.96TeV

Physical Review Letters 106:12 (2011)

Authors:

T Aaltonen, B Álvarez González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, JA Appel, A Apresyan, T Arisawa, A Artikov, J Asaadi, W Ashmanskas, B Auerbach, A Aurisano, F Azfar, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, P Barria, P Bartos, M Bauce, G Bauer, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, I Bizjak, KR Bland, C Blocker, B Blumenfeld, A Bocci, A Bodek, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, A Brisuda, C Bromberg, E Brucken, M Bucciantonio, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, S Cabrera, C Calancha, S Camarda, M Campanelli, M Campbell, F Canelli, A Canepa, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, A Clark, D Clark, G Compostella, ME Convery, J Conway, M Corbo, M Cordelli, CA Cox, DJ Cox, F Crescioli

Abstract:

We report on a measurement of b-hadron lifetimes in the fully reconstructed decay modes B+→J/ψK+, B0→J/ ψK*(892)0, B0→J/ψKs0, and Λb0→J/ψΛ0 using data corresponding to an integrated luminosity of 4.3fb-1, collected by the CDF II detector at the Fermilab Tevatron. The measured lifetimes are τ(B+)=[1.639±0.009(stat)±0.009(syst)] ps, τ(B0)=[1.507±0.010(stat)±0.008(syst)]ps, and τ(Λb0)=[1.537±0.045(stat)±0.014(syst)]ps. The lifetime ratios are τ(B+)/τ(B0)=[1.088±0.009(stat)±0. 004(syst)] and τ(Λb0)/τ(B0)=[1.020±0.030(stat)±0. 008(syst)]. These are the most precise determinations of these quantities from a single experiment. © 2011 American Physical Society.

Search for the rare decays Bs -->mumu and Bd -->mumu

(2011)

Authors:

LHCb Collaboration, R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Amoraal, J Anderson, RB Appleby, O Aquines Gutierrez, L Arrabito, M Artuso, E Aslanides, G Auriemma, S Bachmann, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, A Bates, C Bauer, Th Bauer, A Bay, I Bediaga, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, R Bernet, M-O Bettler, M van Beuzekom, A Bien, S Bifani, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, C Blanks, J Blouw, S Blusk, A Bobrov, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, E Bos, TJV Bowcock, C Bozzi, T Brambach, J van den Brand, J Bressieux, S Brisbane, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, A Bursche, J Buytaert, S Cadeddu, JM Caicedo Carvajal, O Callot, M Calvi, M Calvo Gomez, A Camboni, P Campana, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, G Casse, M Cattaneo, M Charles, Ph Charpentier, N Chiapolini, X Cid Vidal, PJ Clark, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, P Collins, F Constantin, G Conti, A Contu, M Coombes, G Corti, GA Cowan, R Currie, B D'Almagne, C D'Ambrosio, W Da Silva, P David, I De Bonis, S De Capua, M De Cian, F De Lorenzi, JM De Miranda, L De Paula, P De Simone, D Decamp, H Degaudenzi, M Deissenroth, L Del Buono, C Deplano, O Deschamps, F Dettori, J Dickens, H Dijkstra, M Dima, P Diniz Batista, S Donleavy, D Dossett, A Dovbnya, F Dupertuis, R Dzhelyadin, C Eames, S Easo, U Egede, V Egorychev, S Eidelman, D van Eijk, F Eisele, S Eisenhardt, L Eklund, Ch Elsasser, DG d'Enterria, D Esperante Pereira, L Estève, A Falabella, E Fanchini, C Färber, G Fardell, C Farinelli, S Farry, V Fave, V Fernandez Albor, M Ferro-Luzzi, S Filippov, C Fitzpatrick, F Fontanelli, R Forty, M Frank, C Frei, M Frosini, S Furcas, A Gallas Torreira, D Galli, M Gandelman, P Gandini, Y Gao, J-C Garnier, J Garofoli, L Garrido, C Gaspar, N Gauvin, M Gersabeck, T Gershon, Ph Ghez, V Gibson, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, H Gordon, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, G Graziani, A Grecu, S Gregson, B Gui, E Gushchin, Yu Guz, T Gys, G Haefeli, SC Haines, T Hampson, S Hansmann-Menzemer, R Harji, N Harnew, PF Harrison, J He, K Hennessy, P Henrard, JA Hernando Morata, E van Herwijnen, A Hicheur, E Hicks, W Hofmann, K Holubyev, P Hopchev, W Hulsbergen, P Hunt, T Huse, RS Huston, D Hutchcroft, V Iakovenko, P Ilten, J Imong, R Jacobsson, M Jahjah Hussein, E Jans, F Jansen, P Jaton, B Jean-Marie, F Jing, M John, D Johnson, CR Jones, B Jost, F Kapusta, TM Karbach, J Keaveney, U Kerzel, T Ketel, A Keune, B Khanji, YM Kim, M Knecht, S Koblitz, A Konoplyannikov, P Koppenburg, A Kozlinskiy, L Kravchuk, G Krocker, P Krokovny, F Kruse, K Kruzelecki, M Kucharczyk, S Kukulak, R Kumar, T Kvaratskheliya, VN La Thi, D Lacarrere, G Lafferty, A Lai, RW Lambert, G Lanfranchi, C Langenbruch, T Latham, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, O Leroy, T Lesiak, L Li, YY Li, L Li Gioi, M Lieng, M Liles, R Lindner, C Linn, B Liu, G Liu, JH Lopes, E Lopez Asamar, N Lopez-March, J Luisier, B M'charek, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, J Magnin, A Maier, S Malde, RMD Mamunur, G Manca, G Mancinelli, N Mangiafave, U Marconi, R Märki, J Marks, G Martellotti, A Martens, L Martin, A Martín Sánchez, D Martinez Santos, A Massafferri, Z Mathe, C Matteuzzi, M Matveev, V Matveev, E Maurice, B Maynard, A Mazurov, G McGregor, R McNulty, C Mclean, M Meissner, M Merk, J Merkel, M Merkin, R Messi, S Miglioranzi, DA Milanes, M-N Minard, S Monteil, D Moran, P Morawski, JV Morris, R Mountain, I Mous, F Muheim, K Müller, R Muresan, F Murtas, B Muryn, M Musy, J Mylroie-Smith, P Naik, T Nakada, R Nandakumar, J Nardulli, M Nedos, M Needham, N Neufeld, M Nicol, S Nies, V Niess, N Nikitin, A Oblakowska-Mucha, V Obraztsov, S Oggero, O Okhrimenko, R Oldeman, M Orlandea, A Ostankov, B Pal, J Palacios, M Palutan, J Panman, A Papanestis, M Pappagallo, C Parkes, CJ Parkinson, G Passaleva, GD Patel, M Patel, SK Paterson, GN Patrick, C Patrignani, C Pavel -Nicorescu, A Pazos Alvarez, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, DL Perego, E Perez Trigo, A Pérez-Calero Yzquierdo, P Perret, A Petrella, A Petrolini, B Pie Valls, B Pietrzyk, D Pinci, R Plackett, S Playfer, M Plo Casasus, G Polok, A Poluektov, E Polycarpo, D Popov, B Popovici, C Potterat, A Powell, T du Pree, V Pugatch, A Puig Navarro, W Qian, JH Rademacker, B Rakotomiaramanana, I Raniuk, G Raven, S Redford, W Reece, AC dos Reis, S Ricciardi, K Rinnert, DA Roa Romero, P Robbe, E Rodrigues, F Rodrigues, C Rodriguez Cobo, P Rodriguez Perez, GJ Rogers, V Romanovsky, J Rouvinet, T Ruf, H Ruiz, G Sabatino, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, C Salzmann, A Sambade Varela, M Sannino, R Santacesaria, R Santinelli, E Santovetti, M Sapunov, A Sarti, C Satriano, A Satta, M Savrie, D Savrina, P Schaack, M Schiller, S Schleich, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, A Sciubba, M Seco, A Semennikov, K Senderowska, N Serra, J Serrano, B Shao, M Shapkin, I Shapoval, P Shatalov, Y Shcheglov, T Shears, L Shekhtman, O Shevchenko, V Shevchenko, A Shires, E Simioni, HP Skottowe, T Skwarnicki, AC Smith, K Sobczak, FJP Soler, A Solomin, P Somogy, F Soomro, B Souza De Paula, B Spaan, A Sparkes, E Spiridenkov, P Spradlin, F Stagni, O Steinkamp, O Stenyakin, S Stoica, S Stone, B Storaci, U Straumann, N Styles, M Szczekowski, P Szczypka, T Szumlak, S T'Jampens, V Talanov, E Teodorescu, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, S Topp-Joergensen, MT Tran, A Tsaregorodtsev, N Tuning, A Ukleja, P Urquijo, U Uwer, V Vagnoni, G Valenti, R Vazquez Gomez, P Vazquez Regueiro, S Vecchi, JJ Velthuis, M Veltri, K Vervink, B Viaud, I Videau, X Vilasis-Cardona, J Visniakov, A Vollhardt, D Voong, A Vorobyev, An Vorobyev, H Voss, K Wacker, S Wandernoth, J Wang, DR Ward, AD Webber, M Whitehead, D Wiedner, L Wiggers, G Wilkinson, MP Williams, M Williams, FF Wilson, J Wishahi, M Witek, W Witzeling, SA Wotton, K Wyllie, Y Xie, F Xing, Z Yang, G Ybeles Smit, R Young, O Yushchenko, M Zavertyaev, L Zhang, WC Zhang, Y Zhang, A Zhelezov, L Zhong, E Zverev

Search for the rare decays Bs -->mumu and Bd -->mumu

ArXiv 1103.2465 (2011)

Authors:

LHCb Collaboration, R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, P Alvarez Cartelle, AA Alves Jr, S Amato, Y Amhis, J Amoraal, J Anderson, RB Appleby, O Aquines Gutierrez, L Arrabito, M Artuso, E Aslanides, G Auriemma, S Bachmann, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, A Bates, C Bauer, Th Bauer, A Bay, I Bediaga, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, R Bernet, M-O Bettler, M van Beuzekom, A Bien, S Bifani, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, C Blanks, J Blouw, S Blusk, A Bobrov, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, E Bos, TJV Bowcock, C Bozzi, T Brambach, J van den Brand, J Bressieux, S Brisbane, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, A Bursche, J Buytaert, S Cadeddu, JM Caicedo Carvajal, O Callot, M Calvi, M Calvo Gomez, A Camboni, P Campana, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, G Casse, M Cattaneo, M Charles, Ph Charpentier, N Chiapolini, X Cid Vidal, PJ Clark, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, P Collins, F Constantin, G Conti, A Contu, M Coombes, G Corti, GA Cowan, R Currie, B D'Almagne, C D'Ambrosio, W Da Silva, P David, I De Bonis, S De Capua, M De Cian, F De Lorenzi, JM De Miranda, L De Paula, P De Simone, D Decamp, H Degaudenzi, M Deissenroth, L Del Buono, C Deplano, O Deschamps, F Dettori, J Dickens, H Dijkstra, M Dima, P Diniz Batista, S Donleavy, D Dossett, A Dovbnya, F Dupertuis, R Dzhelyadin, C Eames, S Easo, U Egede, V Egorychev, S Eidelman, D van Eijk, F Eisele, S Eisenhardt, L Eklund, Ch Elsasser, DG d'Enterria, D Esperante Pereira, L Estève, A Falabella, E Fanchini, C Färber, G Fardell, C Farinelli, S Farry, V Fave, V Fernandez Albor, M Ferro-Luzzi, S Filippov, C Fitzpatrick, F Fontanelli, R Forty, M Frank, C Frei, M Frosini, S Furcas, A Gallas Torreira, D Galli, M Gandelman, P Gandini, Y Gao, J-C Garnier, J Garofoli, L Garrido, C Gaspar, N Gauvin, M Gersabeck, T Gershon, Ph Ghez, V Gibson, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, H Gordon, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, G Graziani, A Grecu, S Gregson, B Gui, E Gushchin, Yu Guz, T Gys, G Haefeli, SC Haines, T Hampson, S Hansmann-Menzemer, R Harji, N Harnew, PF Harrison, J He, K Hennessy, P Henrard, JA Hernando Morata, E van Herwijnen, A Hicheur, E Hicks, W Hofmann, K Holubyev, P Hopchev, W Hulsbergen, P Hunt, T Huse, RS Huston, D Hutchcroft, V Iakovenko, P Ilten, J Imong, R Jacobsson, M Jahjah Hussein, E Jans, F Jansen, P Jaton, B Jean-Marie, F Jing, M John, D Johnson, CR Jones, B Jost, F Kapusta, TM Karbach, J Keaveney, U Kerzel, T Ketel, A Keune, B Khanji, YM Kim, M Knecht, S Koblitz, A Konoplyannikov, P Koppenburg, A Kozlinskiy, L Kravchuk, G Krocker, P Krokovny, F Kruse, K Kruzelecki, M Kucharczyk, S Kukulak, R Kumar, T Kvaratskheliya, VN La Thi, D Lacarrere, G Lafferty, A Lai, RW Lambert, G Lanfranchi, C Langenbruch, T Latham, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, O Leroy, T Lesiak, L Li, YY Li, L Li Gioi, M Lieng, M Liles, R Lindner, C Linn, B Liu, G Liu, JH Lopes, E Lopez Asamar, N Lopez-March, J Luisier, B M'charek, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, J Magnin, A Maier, S Malde, RMD Mamunur, G Manca, G Mancinelli, N Mangiafave, U Marconi, R Märki, J Marks, G Martellotti, A Martens, L Martin, A Martín Sánchez, D Martinez Santos, A Massafferri, Z Mathe, C Matteuzzi, M Matveev, V Matveev, E Maurice, B Maynard, A Mazurov, G McGregor, R McNulty, C Mclean, M Meissner, M Merk, J Merkel, M Merkin, R Messi, S Miglioranzi, DA Milanes, M-N Minard, S Monteil, D Moran, P Morawski, JV Morris, R Mountain, I Mous, F Muheim, K Müller, R Muresan, F Murtas, B Muryn, M Musy, J Mylroie-Smith, P Naik, T Nakada, R Nandakumar, J Nardulli, M Nedos, M Needham, N Neufeld, M Nicol, S Nies, V Niess, N Nikitin, A Oblakowska-Mucha, V Obraztsov, S Oggero, O Okhrimenko, R Oldeman, M Orlandea, A Ostankov, B Pal, J Palacios, M Palutan, J Panman, A Papanestis, M Pappagallo, C Parkes, CJ Parkinson, G Passaleva, GD Patel, M Patel, SK Paterson, GN Patrick, C Patrignani, C Pavel-Nicorescu, A Pazos Alvarez, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, DL Perego, E Perez Trigo, A Pérez-Calero Yzquierdo, P Perret, A Petrella, A Petrolini, B Pie Valls, B Pietrzyk, D Pinci, R Plackett, S Playfer, M Plo Casasus, G Polok, A Poluektov, E Polycarpo, D Popov, B Popovici, C Potterat, A Powell, T du Pree, V Pugatch, A Puig Navarro, W Qian, JH Rademacker, B Rakotomiaramanana, I Raniuk, G Raven, S Redford, W Reece, AC dos Reis, S Ricciardi, K Rinnert, DA Roa Romero, P Robbe, E Rodrigues, F Rodrigues, C Rodriguez Cobo, P Rodriguez Perez, GJ Rogers, V Romanovsky, J Rouvinet, T Ruf, H Ruiz, G Sabatino, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, C Salzmann, A Sambade Varela, M Sannino, R Santacesaria, R Santinelli, E Santovetti, M Sapunov, A Sarti, C Satriano, A Satta, M Savrie, D Savrina, P Schaack, M Schiller, S Schleich, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, A Sciubba, M Seco, A Semennikov, K Senderowska, N Serra, J Serrano, B Shao, M Shapkin, I Shapoval, P Shatalov, Y Shcheglov, T Shears, L Shekhtman, O Shevchenko, V Shevchenko, A Shires, E Simioni, HP Skottowe, T Skwarnicki, AC Smith, K Sobczak, FJP Soler, A Solomin, P Somogy, F Soomro, B Souza De Paula, B Spaan, A Sparkes, E Spiridenkov, P Spradlin, F Stagni, O Steinkamp, O Stenyakin, S Stoica, S Stone, B Storaci, U Straumann, N Styles, M Szczekowski, P Szczypka, T Szumlak, S T'Jampens, V Talanov, E Teodorescu, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, S Topp-Joergensen, MT Tran, A Tsaregorodtsev, N Tuning, A Ukleja, P Urquijo, U Uwer, V Vagnoni, G Valenti, R Vazquez Gomez, P Vazquez Regueiro, S Vecchi, JJ Velthuis, M Veltri, K Vervink, B Viaud, I Videau, X Vilasis-Cardona, J Visniakov, A Vollhardt, D Voong, A Vorobyev, An Vorobyev, H Voss, K Wacker, S Wandernoth, J Wang, DR Ward, AD Webber, M Whitehead, D Wiedner, L Wiggers, G Wilkinson, MP Williams, M Williams, FF Wilson, J Wishahi, M Witek, W Witzeling, SA Wotton, K Wyllie, Y Xie, F Xing, Z Yang, G Ybeles Smit, R Young, O Yushchenko, M Zavertyaev, L Zhang, WC Zhang, Y Zhang, A Zhelezov, L Zhong, E Zverev

Abstract:

A search for the decays Bs-->mumu and Bd-->mumu is performed with about 37 pb^{-1} of pp collisions at sqrt{s} = 7 TeV collected by the LHCb experiment at the Large Hadron Collider at CERN. The observed numbers of events are consistent with the background expectations. The resulting upper limits on the branching ratios are BR(Bs-->mumu) < 5.6 x 10^{-8} and BR(Bd-->mumu) <1.5 x 10^{-8} at 95% confidence level.