Measurement of the differential branching fraction of the decay
$Λ_b^0\rightarrowΛμ^+μ^-$
ArXiv 1306.2577 (2013)
Authors:
LHCb collaboration, R Aaij, 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 Jr, S Amato, S Amerio, Y Amhis, L Anderlini, J Anderson, R Andreassen, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, C Baesso, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, Th Bauer, A Bay, 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, 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, TJV Bowcock, E Bowen, C Bozzi, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, I Burducea, A Bursche, G Busetto, J Buytaert, S Cadeddu, O Callot, M Calvi, M Calvo Gomez, A Camboni, P Campana, D Campora Perez, A Carbone, G Carboni, R Cardinale, A Cardini, H Carranza-Mejia, L Carson, K Carvalho Akiba, G Casse, L Castillo Garcia, M Cattaneo, Ch Cauet, R Cenci, M Charles, Ph Charpentier, P Chen, N Chiapolini, M Chrzaszcz, K Ciba, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, E Cogneras, P Collins, A Comerma-Montells, A Contu, A Cook, M Coombes, S Coquereau, G Corti, B Couturier, GA Cowan, DC Craik, S Cunliffe, R Currie, C D'Ambrosio, P David, PNY David, A Davis, I De Bonis, K De Bruyn, S De Capua, M De Cian, JM De Miranda, L De Paula, W De Silva, P De Simone, D Decamp, M Deckenhoff, L Del Buono, N Déléage, D Derkach, O Deschamps, F Dettori, A Di Canto, F Di Ruscio, H Dijkstra, M Dogaru, S Donleavy, F Dordei, A Dosil Suárez, D Dossett, A Dovbnya, F Dupertuis, P Durante, R Dzhelyadin, A Dziurda, A Dzyuba, S Easo, U Egede, V Egorychev, S Eidelman, D van Eijk, S Eisenhardt, U Eitschberger, R Ekelhof, L Eklund, I El Rifai, Ch Elsasser, A Falabella, C Färber, G Fardell, C Farinelli, S Farry, V Fave, D Ferguson, V Fernandez Albor, F Ferreira Rodrigues, M Ferro-Luzzi, S Filippov, M Fiore, C Fitzpatrick, M Fontana, F Fontanelli, R Forty, O Francisco, M Frank, C Frei, M Frosini, S Furcas, E Furfaro, A Gallas Torreira, D Galli, M Gandelman, P Gandini, Y Gao, J Garofoli, P Garosi, J Garra Tico, L Garrido, C Gaspar, R Gauld, E Gersabeck, M Gersabeck, T Gershon, Ph Ghez, V Gibson, L Giubega, 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, P Griffith, O Grünberg, B Gui, E Gushchin, Yu Guz, T Gys, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, S Hall, B Hamilton, T Hampson, S Hansmann-Menzemer, N Harnew, ST Harnew, J Harrison, T Hartmann, J He, T Head, V Heijne, K Hennessy, P Henrard, JA Hernando Morata, E van Herwijnen, A Hicheur, E Hicks, D Hill, M Hoballah, M Holtrop, C Hombach, P Hopchev, W Hulsbergen, P Hunt, T Huse, N Hussain, D Hutchcroft, D Hynds, V Iakovenko, M Idzik, P Ilten, R Jacobsson, A Jaeger, E Jans, P Jaton, A Jawahery, F Jing, M John, D Johnson, CR Jones, C Joram, B Jost, M Kaballo, S Kandybei, W Kanso, M Karacson, TM Karbach, IR Kenyon, T Ketel, A Keune, B Khanji, O Kochebina, I Komarov, RF Koopman, P Koppenburg, M Korolev, A Kozlinskiy, L Kravchuk, K Kreplin, M Kreps, G Krocker, P Krokovny, F Kruse, 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, S Leo, O Leroy, T Lesiak, B Leverington, Y Li, L Li Gioi, M Liles, R Lindner, C Linn, B Liu, G Liu, S Lohn, I Longstaff, JH Lopes, N Lopez-March, H Lu, D Lucchesi, J Luisier, H Luo, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, S Malde, G Manca, G Mancinelli, J Maratas, U Marconi, P Marino, R Märki, J Marks, G Martellotti, A Martens, A Martín Sánchez, M Martinelli, D Martinez Santos, D Martins Tostes, A Massafferri, R Matev, Z Mathe, C Matteuzzi, E Maurice, A Mazurov, B Mc Skelly, J McCarthy, A McNab, R McNulty, B Meadows, F Meier, M Meissner, M Merk, DA Milanes, M-N Minard, J Molina Rodriguez, S Monteil, D Moran, P Morawski, A Mordà, MJ Morello, R Mountain, I Mous, F Muheim, K Müller, R Muresan, B Muryn, B Muster, P Naik, T Nakada, R Nandakumar, I Nasteva, M Needham, S Neubert, N Neufeld, AD Nguyen, TD Nguyen, C Nguyen-Mau, M Nicol, V Niess, R Niet, N Nikitin, T Nikodem, A Nomerotski, A Novoselov, A Oblakowska-Mucha, V Obraztsov, S Oggero, S Ogilvy, O Okhrimenko, R Oldeman, M Orlandea, JM Otalora Goicochea, P Owen, A Oyanguren, BK Pal, A Palano, M Palutan, J Panman, A Papanestis, M Pappagallo, C Parkes, CJ Parkinson, G Passaleva, GD Patel, M Patel, GN Patrick, C Patrignani, C Pavel-Nicorescu, A Pazos Alvarez, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, E Perez Trigo, A Pérez-Calero Yzquierdo, P Perret, M Perrin-Terrin, L Pescatore, G Pessina, K Petridis, A Petrolini, A Phan, E Picatoste Olloqui, B Pietrzyk, T Pilař, D Pinci, S Playfer, M Plo Casasus, F Polci, G Polok, A Poluektov, E Polycarpo, A Popov, D Popov, B Popovici, C Potterat, A Powell, J Prisciandaro, A Pritchard, C Prouve, V Pugatch, A Puig Navarro, G Punzi, W Qian, JH Rademacker, B Rakotomiaramanana, MS Rangel, I Raniuk, N Rauschmayr, G Raven, S Redford, MM Reid, AC dos Reis, S Ricciardi, A Richards, K Rinnert, V Rives Molina, DA Roa Romero, P Robbe, DA Roberts, E Rodrigues, P Rodriguez Perez, S Roiser, V Romanovsky, A Romero Vidal, J Rouvinet, T Ruf, F Ruffini, H Ruiz, P Ruiz Valls, G Sabatino, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, V Salustino Guimaraes, C Salzmann, B Sanmartin Sedes, M Sannino, R Santacesaria, C Santamarina Rios, E Santovetti, M Sapunov, A Sarti, C Satriano, A Satta, M Savrie, D Savrina, P Schaack, M Schiller, H Schindler, M Schlupp, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, M Seco, A Semennikov, 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, M Sirendi, T Skwarnicki, NA Smith, E Smith, J Smith, M Smith, MD Sokoloff, FJP Soler, F Soomro, D Souza, 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, L Sun, S Swientek, V Syropoulos, M Szczekowski, P Szczypka, T Szumlak, S T'Jampens, M Teklishyn, E Teodorescu, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, S Tolk, D Tonelli, S Topp-Joergensen, N Torr, E Tournefier, S Tourneur, MT Tran, M Tresch, A Tsaregorodtsev, P Tsopelas, N Tuning, M Ubeda Garcia, A Ukleja, D Urner, A Ustyuzhanin, U Uwer, V Vagnoni, G Valenti, A Vallier, M Van Dijk, R Vazquez Gomez, P Vazquez Regueiro, C Vázquez Sierra, S Vecchi, JJ Velthuis, M Veltri, G Veneziano, M Vesterinen, B Viaud, D Vieira, X Vilasis-Cardona, A Vollhardt, D Volyanskyy, D Voong, A Vorobyev, V Vorobyev, C Voß, H Voss, R Waldi, C Wallace, R Wallace, S Wandernoth, J Wang, DR Ward, NK Watson, AD Webber, D Websdale, M Whitehead, J Wicht, J Wiechczynski, D Wiedner, L Wiggers, G Wilkinson, MP Williams, M Williams, FF Wilson, J Wimberley, J Wishahi, M Witek, SA Wotton, S Wright, S Wu, K Wyllie, Y Xie, Z Xing, Z Yang, R Young, X Yuan, O Yushchenko, M Zangoli, M Zavertyaev, F Zhang, L Zhang, WC Zhang, Y Zhang, A Zhelezov, A Zhokhov, L Zhong, A Zvyagin
Abstract:
The differential branching fraction of the decay
$\Lambda_b^0\rightarrow\Lambda\mu^+\mu^-$ is measured as a function of the
square of the dimuon invariant mass, $q^2$. A yield of $78\pm12$
$\Lambda_b^0\rightarrow\Lambda\mu^+\mu^-$ decays is observed using data,
corresponding to an integrated luminosity of 1.0\,fb$^{-1}$, collected by the
LHCb experiment at a centre-of-mass energy of 7\,TeV. A significant signal is
found in the $q^2$ region above the square of the $J/\psi$ mass, while at
lower-$q^2$ values upper limits are set on the differential branching fraction.
Integrating the differential branching fraction over $q^2$, while excluding the
$J/\psi$ and $\psi(2S)$ regions, gives a branching fraction of
$\BF($\Lambda_b^0\rightarrow\Lambda\mu^+\mu^-$)=(0.96\pm 0.16\stat\pm
0.13\syst\pm 0.21 (\mathrm{norm}))\times 10^{-6}$, where the uncertainties are
statistical, systematic and due to the normalisation mode,
$$\Lambda_b^0\rightarrow J/psi\Lambda$, respectively.
