학술논문

Differential branching fraction and angular analysis of Λb0 → Λμ+μ decays
Document Type
Original Paper
Author
The LHCb collaborationAaij, R.Adeva, B.Adinolfi, M.Affolder, A.Ajaltouni, Z.Akar, S.Albrecht, J.Alessio, F.Alexander, M.Ali, S.Alkhazov, G.Alvarez Cartelle, P.Alves, Jr, A. A.Amato, S.Amerio, S.Amhis, Y.An, L.Anderlini, L.Anderson, J.Andreotti, M.Andrews, J. E.Appleby, R. B.Aquines Gutierrez, O.Archilli, F.Artamonov, A.Artuso, M.Aslanides, E.Auriemma, G.Baalouch, M.Bachmann, S.Back, J. J.Badalov, A.Baesso, C.Baldini, W.Barlow, R. J.Barschel, C.Barsuk, S.Barter, W.Batozskaya, V.Battista, V.Bay, A.Beaucourt, L.Beddow, J.Bedeschi, F.Bediaga, I.Bel, L. J.Belyaev, I.Ben-Haim, E.Bencivenni, G.Benson, S.Benton, J.Berezhnoy, A.Bernet, R.Bertolin, A.Bettler, M.-O.van Beuzekom, M.Bien, A.Bifani, S.Bird, T.Bizzeti, A.Blake, T.Blanc, F.Blouw, J.Blusk, S.Bocci, V.Bondar, A.Bondar, N.Bonivento, W.Borghi, S.Borsato, M.Bowcock, T. J. V.Bowen, E.Bozzi, C.Braun, S.Brett, D.Britsch, M.Britton, T.Brodzicka, J.Brook, N. H.Bursche, A.Buytaert, J.Cadeddu, S.Calabrese, R.Calvi, M.Calvo Gomez, M.Campana, P.Campora Perez, D.Capriotti, L.Carbone, A.Carboni, G.Cardinale, R.Cardini, A.Carniti, P.Carson, L.Carvalho Akiba, K.Casanova Mohr, R.Casse, G.Cassina, L.Castillo Garcia, L.Cattaneo, M.Cauet, Ch.Cavallero, G.Cenci, R.Charles, M.Charpentier, Ph.Chefdeville, M.Chen, S.Cheung, S.-F.Chiapolini, N.Chrzaszcz, M.Cid Vidal, X.Ciezarek, G.Clarke, P. E. L.Clemencic, M.Cliff, H. V.Closier, J.Coco, V.Cogan, J.Cogneras, E.Cogoni, V.Cojocariu, L.Collazuol, G.Collins, P.Comerma-Montells, A.Contu, A.Cook, A.Coombes, M.Coquereau, S.Corti, G.Corvo, M.Counts, I.Couturier, B.Cowan, G. A.Craik, D. C.Crocombe, A. C.Torres, M. CruzCunliffe, S.Currie, R.D’Ambrosio, C.Dalseno, J.David, P. N. Y.Davis, A.De Bruyn, K.De Capua, S.De Cian, M.De Miranda, J. M.De Paula, L.De Silva, W.De Simone, P.Dean, C.-T.Decamp, D.Deckenhoff, M.Del Buono, L.Déléage, N.Derkach, D.Deschamps, O.Dettori, F.Dey, B.Di Canto, A.Di Ruscio, F.Dijkstra, H.Donleavy, S.Dordei, F.Dorigo, M.Dosil Suárez, A.Dossett, D.Dovbnya, A.Dreimanis, K.Dujany, G.Dupertuis, F.Durante, P.Dzhelyadin, R.Dziurda, A.Dzyuba, A.Easo, S.Egede, U.Egorychev, V.Eidelman, S.Eisenhardt, S.Eitschberger, U.Ekelhof, R.Eklund, L.El Rifai, I.Elsasser, Ch.Ely, S.Esen, S.Evans, H. M.Evans, T.Falabella, A.Färber, C.Farinelli, C.Farley, N.Farry, S.Fay, R.Ferguson, D.Fernandez Albor, V.Ferrari, F.Ferreira Rodrigues, F.Ferro-Luzzi, M.Filippov, S.Fiore, M.Fiorini, M.Firlej, M.Fitzpatrick, C.Fiutowski, T.Fol, P.Fontana, M.Fontanelli, F.Forty, R.Francisco, O.Frank, M.Frei, C.Frosini, M.Fu, J.Furfaro, E.Gallas Torreira, A.Galli, D.Gallorini, S.Gambetta, S.Gandelman, M.Gandini, P.Gao, Y.García Pardiñas, J.Garofoli, J.Garra Tico, J.Garrido, L.Gascon, D.Gaspar, C.Gastaldi, U.Gauld, R.Gavardi, L.Gazzoni, G.Geraci, A.Gerick, D.Gersabeck, E.Gersabeck, M.Gershon, T.Ghez, Ph.Gianelle, A.Gianì, S.Gibson, V.Giubega, L.Gligorov, V. V.Göbel, C.Golubkov, D.Golutvin, A.Gomes, A.Gotti, C.Grabalosa Gándara, M.Graciani Diaz, R.Granado Cardoso, L. A.Graugés, E.Graverini, E.Graziani, G.Grecu, A.Greening, E.Gregson, S.Griffith, P.Grillo, L.Grünberg, O.Gui, B.Gushchin, E.Guz, Yu.Gys, T.Hadjivasiliou, C.Haefeli, G.Haen, C.Haines, S. C.Hall, S.Hamilton, B.Hampson, T.Han, X.Hansmann-Menzemer, S.Harnew, N.Harnew, S. T.Harrison, J.He, J.Head, T.Heijne, V.Hennessy, K.Henrard, P.Henry, L.Hernando Morata, J. A.van Herwijnen, E.Heß, M.Hicheur, A.Hill, D.Hoballah, M.Hombach, C.Hulsbergen, W.Humair, T.Hussain, N.Hutchcroft, D.Hynds, D.Idzik, M.Ilten, P.Jacobsson, R.Jaeger, A.Jalocha, J.Jans, E.Jawahery, A.Jing, F.John, M.Johnson, D.Jones, C. R.Joram, C.Jost, B.Jurik, N.Kandybei, S.Kanso, W.Karacson, M.Karbach, T. M.Karodia, S.Kelsey, M.Kenyon, I. R.Kenzie, M.Ketel, T.Khanji, B.Khurewathanakul, C.Klaver, S.Klimaszewski, K.Kochebina, O.Kolpin, M.Komarov, I.Koopman, R. F.Koppenburg, P.Korolev, M.Kravchuk, L.Kreplin, K.Kreps, M.Krocker, G.Krokovny, P.Kruse, F.Kucewicz, W.Kucharczyk, M.Kudryavtsev, V.Kurek, K.Kvaratskheliya, T.La Thi, V. N.Lacarrere, D.Lafferty, G.Lai, A.Lambert, D.Lambert, R. W.Lanfranchi, G.Langenbruch, C.Langhans, B.Latham, T.Lazzeroni, C.Le Gac, R.van Leerdam, J.Lees, J.-P.Lefèvre, R.Leflat, A.Lefrançois, J.Leroy, O.Lesiak, T.Leverington, B.Li, Y.Likhomanenko, T.Liles, M.Lindner, R.Linn, C.Lionetto, F.Liu, B.Lohn, S.Longstaff, I.Lopes, J. H.Lowdon, P.Lucchesi, D.Luo, H.Lupato, A.Luppi, E.Lupton, O.Machefert, F.Maciuc, F.Maev, O.Malde, S.Malinin, A.Manca, G.Mancinelli, G.Manning, P.Mapelli, A.Maratas, J.Marchand, J. F.Marconi, U.Marin Benito, C.Marino, P.Märki, R.Marks, J.Martellotti, G.Martinelli, M.Martinez Santos, D.Martinez Vidal, F.Martins Tostes, D.Massafferri, A.Matev, R.Mathad, A.Mathe, Z.Matteuzzi, C.Mauri, A.Maurin, B.Mazurov, A.McCann, M.McCarthy, J.McNab, A.McNulty, R.Meadows, B.Meier, F.Meissner, M.Merk, M.Milanes, D. A.Minard, M.-N.Mitzel, D. S.Molina Rodriguez, J.Monteil, S.Morandin, M.Morawski, P.Mordà, A.Morello, M. J.Moron, J.Morris, A.-B.Mountain, R.Muheim, F.Müller, K.Mussini, M.Muster, B.Naik, P.Nakada, T.Nandakumar, R.Nasteva, I.Needham, M.Neri, N.Neubert, S.Neufeld, N.Neuner, M.Nguyen, A. D.Nguyen, T. D.Nguyen-Mau, C.Niess, V.Niet, R.Nikitin, N.Nikodem, T.Novoselov, A.O’Hanlon, D. P.Oblakowska-Mucha, A.Obraztsov, V.Ogilvy, S.Okhrimenko, O.Oldeman, R.Onderwater, C. J. G.Osorio Rodrigues, B.Otalora Goicochea, J. M.Otto, A.Owen, P.Oyanguren, A.Palano, A.Palombo, F.Palutan, M.Panman, J.Papanestis, A.Pappagallo, M.Pappalardo, L. L.Parkes, C.Passaleva, G.Patel, G. D.Patel, M.Patrignani, C.Pearce, A.Pellegrino, A.Penso, G.Pepe Altarelli, M.Perazzini, S.Perret, P.Pescatore, L.Petridis, K.Petrolini, A.Picatoste Olloqui, E.Pietrzyk, B.Pilař, T.Pinci, D.Pistone, A.Playfer, S.Plo Casasus, M.Poikela, T.Polci, F.Poluektov, A.Polyakov, I.Polycarpo, E.Popov, A.Popov, D.Popovici, B.Potterat, C.Price, E.Price, J. D.Prisciandaro, J.Pritchard, A.Prouve, C.Pugatch, V.Puig Navarro, A.Punzi, G.Qian, W.Quagliani, R.Rachwal, B.Rademacker, J. H.Rakotomiaramanana, B.Rama, M.Rangel, M. S.Raniuk, I.Rauschmayr, N.Raven, G.Redi, F.Reichert, S.Reid, M. M.dos Reis, A. C.Ricciardi, S.Richards, S.Rihl, M.Rinnert, K.Rives Molina, V.Robbe, P.Rodrigues, A. B.Rodrigues, E.Rodriguez Lopez, J. A.Rodriguez Perez, P.Roiser, S.Romanovsky, V.Romero Vidal, A.Rotondo, M.Rouvinet, J.Ruf, T.Ruiz, H.Ruiz Valls, P.Saborido Silva, J. J.Sagidova, N.Sail, P.Saitta, B.Salustino Guimaraes, V.Sanchez Mayordomo, C.Sanmartin Sedes, B.Santacesaria, R.Santamarina Rios, C.Santovetti, E.Sarti, A.Satriano, C.Satta, A.Saunders, D. 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.Semennikov, A.Sepp, I.Serra, N.Serrano, J.Sestini, L.Seyfert, P.Shapkin, M.Shapoval, I.Shcheglov, Y.Shears, T.Shekhtman, L.Shevchenko, V.Shires, A.Silva Coutinho, R.Simi, G.Sirendi, M.Skidmore, N.Skillicorn, I.Skwarnicki, T.Smith, N. A.Smith, E.Smith, E.Smith, J.Smith, M.Snoek, H.Sokoloff, M. D.Soler, F. J. P.Soomro, F.Souza, D.Souza De Paula, B.Spaan, B.Spradlin, P.Sridharan, S.Stagni, F.Stahl, M.Stahl, S.Steinkamp, O.Stenyakin, O.Sterpka, F.Stevenson, S.Stoica, S.Stone, S.Storaci, B.Stracka, S.Straticiuc, M.Straumann, U.Stroili, R.Sun, L.Sutcliffe, W.Swientek, K.Swientek, S.Syropoulos, V.Szczekowski, M.Szczypka, P.Szumlak, T.T’Jampens, S.Teklishyn, M.Tellarini, G.Teubert, F.Thomas, C.Thomas, E.van Tilburg, J.Tisserand, V.Tobin, M.Todd, J.Tolk, S.Tomassetti, L.Tonelli, D.Topp-Joergensen, S.Torr, N.Tournefier, E.Tourneur, S.Trabelsi, K.Tran, M. T.Tresch, M.Trisovic, A.Tsaregorodtsev, A.Tsopelas, P.Tuning, N.Ukleja, A.Ustyuzhanin, A.Uwer, U.Vacca, C.Vagnoni, V.Valenti, G.Vallier, A.Vazquez Gomez, R.Vazquez Regueiro, P.Vázquez Sierra, C.Vecchi, S.Velthuis, J. J.Veltri, M.Veneziano, G.Vesterinen, M.Viana Barbosa, J. V.Viaud, B.Vieira, D.Vieites Diaz, M.Vilasis-Cardona, X.Vollhardt, A.Volyanskyy, D.Voong, D.Vorobyev, A.Vorobyev, V.Voß, C.de Vries, J. A.Waldi, R.Wallace, C.Wallace, R.Walsh, J.Wandernoth, S.Wang, J.Ward, D. R.Watson, N. K.Websdale, D.Weiden, A.Whitehead, M.Wiedner, D.Wilkinson, G.Wilkinson, M.Williams, M.Williams, M. P.Williams, M.Wilson, F. F.Wimberley, J.Wishahi, J.Wislicki, W.Witek, M.Wormser, G.Wotton, S. A.Wright, S.Wyllie, K.Xie, Y.Xu, Z.Yang, Z.Yuan, X.Yushchenko, O.Zangoli, M.Zavertyaev, M.Zhang, L.Zhang, Y.Zhelezov, A.Zhokhov, A.Zhong, L.
Source
Journal of High Energy Physics. 2015(6)
Subject
Rare decay
Hadron-Hadron Scattering
Branching fraction
B physics
Flavour Changing Neutral Currents
Language
English
ISSN
1029-8479
Abstract
Abstract: The differential branching fraction of the rare decay Λb0 → Λμ+μ is measured as a function of q2, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment. Evidence of signal is observed in the q2 region below the square of the J/ψ mass. Integrating over 15 < q2< 20 GeV2/c4 the differential branching fraction is measured asdℬΛb0→Λμ+μ−/dq2=1.18−0.08+0.09±0.03±0.27×10−7GeV2/c4−1,AFBℓ=−0.05±0.09stat±0.03systandAFBh=−0.29±0.07stat±0.03syst.where the uncertainties are statistical, systematic and due to the normalisation mode, Λb0 → J/ψΛ, respectively. In the q2 intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (AFB) and hadron (AFBh) systems are measured for the first time. In the range 15 < q2< 20 GeV2/c4 they are found to bedℬΛb0→Λμ+μ−/dq2=1.18−0.08+0.09±0.03±0.27×10−7GeV2/c4−1,AFBℓ=−0.05±0.09stat±0.03systandAFBh=−0.29±0.07stat±0.03syst.