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Evidence for CP violation in time-integrated D0 → h-h+ decay rates

Physical Review Letters 108:11 (2012)

Authors:

R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Anderson, RB Appleby, O Aquines Gutierrez, F Archilli, L Arrabito, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, A Bates, C Bauer, T Bauer, A Bay, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, J Benton, R Bernet, MO Bettler, M Van Beuzekom, A Bien, S Bifani, T Bird, 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, T J.v. Bowcock, C Bozzi, T Brambach, J Van Den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, I Burducea, A Bursche, J Buytaert, S Cadeddu, 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, C Cauet, M Charles, P Charpentier, N Chiapolini, K Ciba, X Cid Vidal

Abstract:

A search for time-integrated CP violation in D0 → h-h+ (h = K, π) decays is presented using 0.62 fb-1 of data collected by LHCb in 2011. The flavor of the charm meson is determined by the charge of the slow pion in the D∗+ → D0π+ and D∗- → D¯0π- decay chains. The difference in CP asymmetry between D0 → K-K+ and D0 → π-π+, ΔACP ≈ ACP(K-K+)-ACP(π-π+), is measured to be [-0.82 ± 0.21(stat) ± 0.11(syst)]%. This differs from the hypothesis of CP conservation by 3.5 standard deviations. © 2012 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.
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Measurement of the CP-violating phase s in the decay Bs0→J/ψ

Physical Review Letters 108:10 (2012)

Authors:

R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Anderson, RB Appleby, O Aquines Gutierrez, F Archilli, L Arrabito, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, A Bates, C Bauer, T Bauer, A Bay, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, J Benton, R Bernet, MO Bettler, M Van Beuzekom, A Bien, S Bifani, T Bird, 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, TJV Bowcock, C Bozzi, T Brambach, J Van Den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, I Burducea, A Bursche, J Buytaert, S Cadeddu, 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, C Cauet, M Charles, P Charpentier, N Chiapolini, K Ciba, X Cid Vidal

Abstract:

We present a measurement of the time-dependent CP-violating asymmetry in Bs0→J/ψ decays, using data collected with the LHCb detector at the LHC. The decay time distribution of Bs0→J/ψ is characterized by the decay widths Γ H and Γ L of the heavy and light mass eigenstates, respectively, of the Bs0-B̄s0 system and by a CP-violating phase s. In a sample of about 8500 Bs0→J/ψevents isolated from 0.37fb -1 of pp collisions at √s=7TeV, we measure s=0.15±0.18(stat)±0.06(syst)rad. We also find an average Bs0 decay width Γ s (Γ L+Γ H)/2=0.657±0.009(stat)±0.008(syst)ps -1 and a decay width difference ΔΓ s Γ L- Γ H=0.123±0.029(stat)±0.011(syst)ps -1. Our measurement is insensitive to the transformation ( s, ΔΓ s) (π- s,-ΔΓ s). © 2012 CERN. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
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Search for lepton number violating decays B +→π -μ +μ + and B +→K -μ +μ +

Physical Review Letters 108:10 (2012)

Authors:

R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Anderson, RB Appleby, O Aquines Gutierrez, F Archilli, L Arrabito, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, A Bates, C Bauer, T Bauer, A Bay, I Bediaga, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, J Benton, R Bernet, MO 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, TJV Bowcock, C Bozzi, T Brambach, J Van Den Brand, J Bressieux, D Brett, S Brisbane, M Britsch, T Britton, NH Brook, H Brown, A Büchler-Germann, I Burducea, 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, P Charpentier, N Chiapolini, K Ciba, X Cid Vidal, G Ciezarek

Abstract:

A search is performed for the lepton number violating decay B +→h -μ +μ +, where h - represents a K - or a π -, using an integrated luminosity of 36pb -1 of data collected with the LHCb detector. The decay is forbidden in the standard model but allowed in models with a Majorana neutrino. No signal is observed in either channel and limits of B(B +→K -μ +μ +)<5. 4×10 -8 and B(B +→π -μ +μ +)<5.8×10 -8 are set at the 95% confidence level. These improve the previous best limits by factors of 40 and 30, respectively. © 2012 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the http://creativecommons.org/licenses/by/3.0/. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
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First evidence of direct CP violation in charmless two-body decays of Bs mesons

(2012)

Authors:

LHCb collaboration, R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Anderson, RB Appleby, O Aquines Gutierrez, F Archilli, L Arrabito, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, A Bates, C Bauer, Th Bauer, A Bay, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, J Benton, R Bernet, M-O Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, 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, TJV Bowcock, C Bozzi, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, K de Bruyn, A Büchler-Germann, I Burducea, A Bursche, J Buytaert, S Cadeddu, 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, Ch Cauet, M Charles, Ph Charpentier, N Chiapolini, K Ciba, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, P Collins, A Comerma-Montells, A Contu, A Cook, M Coombes, G Corti, B Couturier, GA Cowan, R Currie, C D'Ambrosio, P David, PNY David, I De Bonis, S De Capua, M De Cian, F De Lorenzi, JM De Miranda, L De Paula, P De Simone, D Decamp, M Deckenhoff, H Degaudenzi, L Del Buono, C Deplano, D Derkach, O Deschamps, F Dettori, J Dickens, H Dijkstra, P Diniz Batista, F Domingo Bonal, S Donleavy, F Dordei, A Dosil Suárez, D Dossett, A Dovbnya, F Dupertuis, R Dzhelyadin, A Dziurda, S Easo, U Egede, V Egorychev, S Eidelman, D van Eijk, F Eisele, S Eisenhardt, R Ekelhof, L Eklund, Ch Elsasser, D Elsby, D Esperante Pereira, A Falabella, C Färber, G Fardell, C Farinelli, S Farry, V Fave, V Fernandez Albor, M Ferro-Luzzi, S Filippov, C Fitzpatrick, M Fontana, F Fontanelli, R Forty, O Francisco, M Frank, C Frei, M Frosini, S Furcas, A Gallas Torreira, D Galli, M Gandelman, P Gandini, Y Gao, J-C Garnier, J Garofoli, J Garra Tico, L Garrido, D Gascon, C Gaspar, R Gauld, 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, E Greening, S Gregson, B Gui, E Gushchin, Yu Guz, T Gys, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, T Hampson, S Hansmann-Menzemer, R Harji, N Harnew, J Harrison, PF Harrison, T Hartmann, J He, V Heijne, K Hennessy, P Henrard, JA Hernando Morata, E van Herwijnen, E Hicks, K Holubyev, P Hopchev, W Hulsbergen, P Hunt, T Huse, RS Huston, D Hutchcroft, D Hynds, V Iakovenko, P Ilten, J Imong, R Jacobsson, A Jaeger, M Jahjah Hussein, E Jans, F Jansen, P Jaton, B Jean-Marie, F Jing, M John, D Johnson, CR Jones, B Jost, M Kaballo, S Kandybei, M Karacson, TM Karbach, J Keaveney, IR Kenyon, U Kerzel, T Ketel, A Keune, B Khanji, YM Kim, M Knecht, RF Koopman, P Koppenburg, M Korolev, A Kozlinskiy, L Kravchuk, K Kreplin, M Kreps, G Krocker, P Krokovny, F Kruse, K Kruzelecki, M Kucharczyk, V Kudryavtsev, T Kvaratskheliya, VN La Thi, D Lacarrere, G Lafferty, A Lai, D Lambert, RW Lambert, E Lanciotti, G Lanfranchi, C Langenbruch, T Latham, C Lazzeroni, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, O Leroy, T Lesiak, L Li, L Li Gioi, M Lieng, M Liles, R Lindner, C Linn, B Liu, G Liu, J von Loeben, JH Lopes, E Lopez Asamar, N Lopez-March, H Lu, J Luisier, A Mac Raighne, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, J Magnin, 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, M Martinelli, D Martinez Santos, A Massafferri, Z Mathe, C Matteuzzi, M Matveev, E Maurice, B Maynard, A Mazurov, G McGregor, R McNulty, M Meissner, M Merk, J Merkel, S Miglioranzi, DA Milanes, M-N Minard, J Molina Rodriguez, S Monteil, D Moran, P Morawski, R Mountain, I Mous, F Muheim, K Müller, R Muresan, B Muryn, B Muster, J Mylroie-Smith, P Naik, T Nakada, R Nandakumar, I Nasteva, M Needham, N Neufeld, AD Nguyen, C Nguyen-Mau, M Nicol, V Niess, N Nikitin, A Nomerotski, A Novoselov, A Oblakowska-Mucha, V Obraztsov, S Oggero, S Ogilvy, O Okhrimenko, R Oldeman, M Orlandea, JM Otalora Goicochea, P Owen, K Pal, J Palacios, A Palano, 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, M Perrin-Terrin, G Pessina, A Petrolini, A Phan, E Picatoste Olloqui, B Pie Valls, B Pietrzyk, T Pilař, D Pinci, R Plackett, S Playfer, M Plo Casasus, G Polok, A Poluektov, E Polycarpo, D Popov, B Popovici, C Potterat, A Powell, J Prisciandaro, V Pugatch, A Puig Navarro, W Qian, JH Rademacker, B Rakotomiaramanana, MS Rangel, I Raniuk, G Raven, S Redford, MM Reid, AC dos Reis, S Ricciardi, A Richards, K Rinnert, DA Roa Romero, P Robbe, E Rodrigues, F Rodrigues, P Rodriguez Perez, GJ Rogers, S Roiser, V Romanovsky, M Rosello, J Rouvinet, T Ruf, H Ruiz, G Sabatino, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, C Salzmann, M Sannino, R Santacesaria, C Santamarina Rios, R Santinelli, E Santovetti, M Sapunov, A Sarti, C Satriano, A Satta, M Savrie, D Savrina, P Schaack, M Schiller, S Schleich, M Schlupp, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, M Seco, A Semennikov, K Senderowska, I Sepp, N Serra, J Serrano, P Seyfert, M Shapkin, I Shapoval, P Shatalov, Y Shcheglov, T Shears, L Shekhtman, O Shevchenko, V Shevchenko, A Shires, R Silva Coutinho, T Skwarnicki, NA Smith, E Smith, K Sobczak, FJP Soler, A Solomin, F Soomro, B Souza De Paula, B Spaan, A Sparkes, P Spradlin, F Stagni, S Stahl, O Steinkamp, S Stoica, S Stone, B Storaci, M Straticiuc, U Straumann, VK Subbiah, S Swientek, M Szczekowski, P Szczypka, T Szumlak, S T'Jampens, E Teodorescu, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, S Topp-Joergensen, N Torr, E Tournefier, S Tourneur, MT Tran, A Tsaregorodtsev, N Tuning, M Ubeda Garcia, A Ukleja, P Urquijo, U Uwer, V Vagnoni, G Valenti, R Vazquez Gomez, P Vazquez Regueiro, S Vecchi, JJ Velthuis, M Veltri, B Viaud, I Videau, D Vieira, X Vilasis-Cardona, J Visniakov, A Vollhardt, D Volyanskyy, D Voong, A Vorobyev, H Voss, R Waldi, S Wandernoth, J Wang, DR Ward, NK Watson, AD Webber, D Websdale, 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 Xing, Z Yang, R Young, O Yushchenko, M Zangoli, M Zavertyaev, F Zhang, L Zhang, WC Zhang, Y Zhang, A Zhelezov, L Zhong, A Zvyagin
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Measurement of b-hadron masses

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 708:3-5 (2012) 241-248

Authors:

R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, Y Amhis, J Anderson, RB Appleby, O Aquines Gutierrez, F Archilli, L Arrabito, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, DS Bailey, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, A Bates, C Bauer, T Bauer, A Bay, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, J Benton, R Bernet, MO Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, 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, TJV Bowcock, C Bozzi, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, A Büchler-Germann, I Burducea, A Bursche, J Buytaert, S Cadeddu, 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, C Cauet, M Charles, P Charpentier, N Chiapolini, K Ciba, X Cid Vidal, G Ciezarek

Abstract:

Measurements of b-hadron masses are performed with the exclusive decay modes B +→J/ψK +, B 0→J/ψK +, B0→J/ψKS0, Bs0→J/ψφ and Λb0→J/ψΛ using an integrated luminosity of 35pb -1 collected in pp collisions at a centre-of-mass energy of 7 TeV by the LHCb experiment. The momentum scale is calibrated with J/ψ→μ +μ - decays and verified to be known to a relative precision of 2 ×10 -4 using other two-body decays. The results are more precise than previous measurements, particularly in the case of the Bs0 and Λb0 masses. © 2012 CERN.
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