Measurement of the Z+b-jet cross-section in pp collisions at(Formula presented.)= 7 TeV in the forward region

Journal of High Energy Physics 2015:1 (2015) 1-15

Authors:

L Zhong, R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, J Anderson, R Andreassen, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, S Eidelman, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, AB Bertolin, MO Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, A Bursche, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M Calvo Gomez, P Campana, D Campora Perez, L Capriotti, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, RCM Casanova Mohr, G Casse

Abstract:

Abstract: The associated production of a Z boson or an off-shell photon γ* with a bottom quark in the forward region is studied using proton-proton collisions at a centre-of-mass energy of 7 TeV. The Z bosons are reconstructed in the Z/γ* → μ+μ final state from muons with a transverse momentum larger than 20 GeV, while two transverse momentum thresholds are considered for jets (10 GeV and 20 GeV). Both muons and jets are reconstructed in the pseudorapidity range 2.0 < η < 4.5. The results are based on data corresponding to 1.0 fb−1 recorded in 2011 with the LHCb detector. The measurement of the Z+b-jet cross-section is normalized to the Z+jet cross-section. The measured cross-sections are(Formula presented.)for pT(jet) > 10 GeV, and(Formula presented.)for pT(jet) > 20 GeV.[Figure not available: see fulltext.].

Search for the lepton flavour violating decay τ− → μ−μ+μ−

Journal of High Energy Physics 2015:2 (2015) 1-20

Authors:

L Zhong, R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, J Anderson, R Andreassen, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, A Badalov, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, MO Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, T Brambach, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, H Brown, A Bursche, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M Calvo Gomez, P Campana, D Campora Perez, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, G Casse, L Cassina

Abstract:

Abstract: A search for the lepton flavour violating decay τ → μμ+μ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb−1 of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb−1 at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, B(τ → μμ+μ) < 4.6 × 10−8

Study of the rare B0s and B0 decays into the π+π-μ+μ- final state

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 743:1 (2015) 46-55

Authors:

R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, J Anderson, R Andreassen, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, A Badalov, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, A Bertolin, MO Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, A Bursche, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M Calvo Gomez, P Campana, D Campora Perez

Abstract:

© 2015 The Authors. A search for the rare decays B0s → π+π-μ+μ- and B0 → π+π-μ+μ- is performed in a data set corresponding to an integrated luminosity of 3.0fb-1collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay B0s → π+π-μ+μ-and the first evidence of the decay B0 → π+π-μ+μ-are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(B0s → π+pπμ+μ-) =(8.6 ±1.5(stat) ±0.7(syst) ±0.7 (norm)) ×10-8 and B(B0 → π+π-μ+μ-) =(2.11±0.51(stat)±0.15(syst)±0.16(norm)) × 10-8, where the third uncertainty is due to the branching fraction of the decay B0 → J/ψ(→ μ+μ-)K*(892)0(→ K+p-), used as a normalisation.

Study of η − η mixing from measurement of B (s)0 → J/ψη(′) decay rates

Journal of High Energy Physics 2015:1 (2015) 1-24

Authors:

LHCb collaboration The, R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, L Anderlini, J Anderson, R Andreassen, M Andreotti, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, G Auriemma, M Baalouch, S Bachmann, JJ Back, A Badalov, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, AB Bertolin, MO Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, H Brown, A Bursche, J Buytaert, S Cadeddu, R Calabrese, R Calabrese, M Calvi, M Calvi, M Calvo Gomez, M Calvo Gomez, P Campana

Abstract:

© 2015, The Author(s). Abstract: A study of B and Bs meson decays into J/ψ η and J/ψ η final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, collected by the LCHb experiment and corresponding to 3.0 fb−1 of integrated luminosity. The decay B0 → J/ψ η is observed for the first time. The following ratios of branching fractions are measured: (Formula Presented) where the third uncertainty is related to the present knowledge of fs/fd, the ratio between the probabilities for a b quark to form a Bs or a B0 meson. The branching fraction ratios are used to determine the parameters of η − η meson mixing. In addition, the first evidence for the decay Bs → ψ(2S)η is reported, and the relative branching fraction is measured, (Formula Presented) where the third uncertainty is due to the limited knowledge of the branching fractions of J/ψ and ψ(2S) mesons.

Measurement of the Z+b-jet cross-section in pp collisions at s = 7 TeV in the forward region

Journal of High Energy Physics Springer Nature 2015:1 (2015) 64

Authors:

The LHCb collaboration, R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, J Anderson, R Andreassen, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, A Badalov, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, AB Bertolin, M-O Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, M Borsato, TJV Bowcock, E Bowen, C Bozzi, D Brett, M Britsch, T Britton, J Brodzicka, NH Brook, A Bursche, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M Calvo Gomez, P Campana, D Campora Perez, L Capriotti, A Carbone, G Carboni, R Cardinale, A Cardini, L Carson, K Carvalho Akiba, RCM Casanova Mohr, G Casse, L Cassina, L Castillo Garcia, M Cattaneo, Ch Cauet, R Cenci, M Charles, Ph Charpentier, M Chefdeville, S Chen, S-F Cheung, N Chiapolini, M Chrzaszcz, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, V Coco, J Cogan, E Cogneras, V Cogoni, L Cojocariu, G Collazuol, P Collins, A Comerma-Montells, A Contu, A Cook, M Coombes, S Coquereau, G Corti, M Corvo, I Counts, B Couturier, GA Cowan, DC Craik, AC Crocombe, M Cruz Torres, S Cunliffe, R Currie, C D’Ambrosio, J Dalseno, P David, PNY David, A Davis, K De Bruyn, S De Capua, M De Cian, JM De Miranda, L De Paula, W De Silva, P De Simone, C-T Dean, D Decamp, M Deckenhoff, L Del Buono, N Déléage, D Derkach, O Deschamps, F Dettori, B Dey, A Di Canto, A Di Domenico, H Dijkstra, S Donleavy, F Dordei, M Dorigo, A Dosil Suárez, D Dossett, A Dovbnya, K Dreimanis, G Dujany, F Dupertuis, P Durante, R Dzhelyadin, A Dziurda, A Dzyuba, S Easo, U Egede, V Egorychev, S Eidelman, S Eisenhardt, U Eitschberger, R Ekelhof, L Eklund, I El Rifai, Ch Elsasser, S Ely, S Esen, H-M Evans, T Evans, A Falabella, C Färber, C Farinelli, N Farley, S Farry, R Fay, D Ferguson, V Fernandez Albor, F Ferreira Rodrigues, M Ferro-Luzzi, S Filippov, M Fiore, M Fiorini, M Firlej, C Fitzpatrick, T Fiutowski, P Fol, M Fontana, F Fontanelli, R Forty, O Francisco, M Frank, C Frei, M Frosini, J Fu, E Furfaro, A Gallas Torreira, D Galli, S Gallorini, S Gambetta, M Gandelman, P Gandini, Y Gao, J García Pardiñas, J Garofoli, J Garra Tico, L Garrido, D Gascon, C Gaspar, U Gastaldi, R Gauld, L Gavardi, G Gazzoni, A Geraci, E Gersabeck, M Gersabeck, T Gershon, Ph Ghez, A Gianelle, S Gianì, V Gibson, L Giubega, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, C Gotti, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, E Graverini, G Graziani, A Grecu, E Greening, S Gregson, P Griffith, L Grillo, O Grünberg, B Gui, E Gushchin, Yu Guz, T Gys, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, S Hall, B Hamilton, T Hampson, X Han, S Hansmann-Menzemer, N Harnew, ST Harnew, J Harrison, J He, T Head, V Heijne, K Hennessy, P Henrard, L Henry, JA Hernando Morata, E van Herwijnen, M Heß, A Hicheur, D Hill, M Hoballah, C Hombach, W Hulsbergen, N Hussain, D Hutchcroft, D Hynds, M Idzik, P Ilten, R Jacobsson, A Jaeger, J Jalocha, E Jans, A Jawahery, F Jing, M John, D Johnson, CR Jones, C Joram, B Jost, N Jurik, S Kandybei, W Kanso, M Karacson, TM Karbach, S Karodia, M Kelsey, IR Kenyon, T Ketel, B Khanji, C Khurewathanakul, S Klaver, K Klimaszewski, O Kochebina, M Kolpin, I Komarov, RF Koopman, P Koppenburg, M Korolev, L Kravchuk, K Kreplin, M Kreps, G Krocker, P Krokovny, F Kruse, W Kucewicz, M Kucharczyk, V Kudryavtsev, K Kurek, T Kvaratskheliya, VN La Thi, D Lacarrere, G Lafferty, A Lai, D Lambert, RW Lambert, G Lanfranchi, C Langenbruch, B Langhans, T Latham, C Lazzeroni, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, O Leroy, T Lesiak, B Leverington, Y Li, T Likhomanenko, M Liles, R Lindner, C Linn, F Lionetto, B Liu, S Lohn, I Longstaff, JH Lopes, P Lowdon, D Lucchesi, H Luo, A Lupato, E Luppi, O Lupton, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, S Malde, A Malinin, G Manca, G Mancinelli, A Mapelli, J Maratas, JF Marchand, U Marconi, C Marin Benito, P Marino, R Märki, J Marks, G Martellotti, M Martinelli, D Martinez Santos, F Martinez Vidal, D Martins Tostes, A Massafferri, R Matev, Z Mathe, C Matteuzzi, A Mazurov, M McCann, J McCarthy, A McNab, R McNulty, B McSkelly, B Meadows, F Meier, M Meissner, M Merk, DA Milanes, M-N Minard, N Moggi, J Molina Rodriguez, S Monteil, M Morandin, P Morawski, A Mordà, MJ Morello, J Moron, A-B Morris, R Mountain, F Muheim, K Müller, M Mussini, B Muster, P Naik, T Nakada, R Nandakumar, I Nasteva, M Needham, N Neri, S Neubert, N Neufeld, M Neuner, AD Nguyen, TD Nguyen, C Nguyen-Mau, M Nicol, V Niess, R Niet, N Nikitin, T Nikodem, A Novoselov, DP O’Hanlon, A Oblakowska-Mucha, V Obraztsov, S Ogilvy, O Okhrimenko, R Oldeman, CJG Onderwater, M Orlandea, B Osorio Rodrigues, JM Otalora Goicochea, A Otto, P Owen, A Oyanguren, BK Pal, A Palano, F Palombo, M Palutan, J Panman, A Papanestis, M Pappagallo, LL Pappalardo, C Parkes, CJ Parkinson, G Passaleva, GD Patel, M Patel, C Patrignani, A Pearce, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, P Perret, L Pescatore, E Pesen, K Petridis, A Petrolini, E Picatoste Olloqui, B Pietrzyk, T Pilař, D Pinci, A Pistone, S Playfer, M Plo Casasus, F Polci, A Poluektov, I Polyakov, E Polycarpo, A Popov, D Popov, B Popovici, C Potterat, E Price, JD Price, J Prisciandaro, A Pritchard, C Prouve, V Pugatch, A Puig Navarro, G Punzi, W Qian, B Rachwal, JH Rademacker, B Rakotomiaramanana, M Rama, MS Rangel, I Raniuk, N Rauschmayr, G Raven, F Redi, S Reichert, MM Reid, AC dos Reis, S Ricciardi, S Richards, M Rihl, K Rinnert, V Rives Molina, P Robbe, AB Rodrigues, E Rodrigues, P Rodriguez Perez, S Roiser, V Romanovsky, A Romero Vidal, M Rotondo, J Rouvinet, T Ruf, H Ruiz, P Ruiz Valls, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, V Salustino Guimaraes, C Sanchez Mayordomo, B Sanmartin Sedes, R Santacesaria, C Santamarina Rios, E Santovetti, A Sarti, C Satriano, A Satta, DM Saunders, D Savrina, M Schiller, H Schindler, M Schlupp, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, A Semennikov, I Sepp, N Serra, J Serrano, L Sestini, P Seyfert, M Shapkin, I Shapoval, Y Shcheglov, T Shears, L Shekhtman, V Shevchenko, A Shires, R Silva Coutinho, G Simi, M Sirendi, N Skidmore, I Skillicorn, T Skwarnicki, NA Smith, E Smith, E Smith, J Smith, M Smith, H Snoek, MD Sokoloff, FJP Soler, F Soomro, D Souza, B Souza De Paula, B Spaan, P Spradlin, S Sridharan, F Stagni, M Stahl, S Stahl, O Steinkamp, O Stenyakin, F Sterpka, S Stevenson, S Stoica, S Stone, B Storaci, S Stracka, M Straticiuc, U Straumann, R Stroili, L Sun, W Sutcliffe, K Swientek, S Swientek, V Syropoulos, M Szczekowski, P Szczypka, T Szumlak, S T’Jampens, M Teklishyn, G Tellarini, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, J Todd, S Tolk, L Tomassetti, D Tonelli, S Topp-Joergensen, N Torr, E Tournefier, S Tourneur, MT Tran, M Tresch, A Trisovic, A Tsaregorodtsev, P Tsopelas, N Tuning, M Ubeda Garcia, A Ukleja, A Ustyuzhanin, U Uwer, C Vacca, V Vagnoni, G Valenti, A Vallier, R Vazquez Gomez, P Vazquez Regueiro, C Vázquez Sierra, S Vecchi, JJ Velthuis, M Veltri, G Veneziano, M Vesterinen, JVVB Viana Barbosa, B Viaud, D Vieira, M Vieites Diaz, X Vilasis-Cardona, A Vollhardt, D Volyanskyy, D Voong, A Vorobyev, V Vorobyev, C Voß, JA de Vries, R Waldi, C Wallace, R Wallace, J Walsh, S Wandernoth, J Wang, DR Ward, NK Watson, D Websdale, M Whitehead, D Wiedner, G Wilkinson, M Wilkinson, MP Williams, M Williams, HW Wilschut, FF Wilson, J Wimberley, J Wishahi, W Wislicki, M Witek, G Wormser, SA Wotton, S Wright, K Wyllie, Y Xie, Z Xing, Z Xu, Z Yang, X Yuan, O Yushchenko, M Zangoli, M Zavertyaev, L Zhang, WC Zhang, Y Zhang, A Zhelezov, A Zhokhov, L Zhong