A new algorithm for identifying the flavour of $B_s^0$ mesons at LHCb
Creators: name: LHCb Collaboration
name: Aaij, R.
name: Beteta, C. Abellán
name: Adeva, B.
name: Adinolfi, M.
name: Affolder, A.
name: Ajaltouni, Z.
name: Akar, S.
name: Albrecht, J.
name: Alessio, F.
name: Alexander, M.
name: Ali, S.
name: Alkhazov, G.
name: Cartelle, P. Alvarez
name: Alves, A. A.
name: Amato, S.
name: Amerio, S.
name: Amhis, Y.
name: An, L.
name: Anderlini, L.
name: Andreassi, G.
name: Andreotti, M.
name: Andrews, J. E.
name: Appleby, R. B.
name: Gutierrez, O. Aquines
name: Archilli, F.
name: d'Argent, P.
name: Artamonov, A.
name: Artuso, M.
name: Aslanides, E.
name: Auriemma, G.
name: Baalouch, M.
name: Bachmann, S.
name: Back, J. J.
name: Badalov, A.
name: Baesso, C.
name: Baldini, W.
name: Barlow, R. J.
name: Barschel, C.
name: Barsuk, S.
name: Barter, W.
name: Batozskaya, V.
name: Battista, V.
name: Bay, A.
name: Beaucourt, L.
name: Beddow, J.
name: Bedeschi, F.
name: Bediaga, I.
name: Bel, L. J.
name: Bellee, V.
name: Belloli, N.
name: Belyaev, I.
name: Ben-Haim, E.
name: Bencivenni, G.
name: Benson, S.
name: Benton, J.
name: Berezhnoy, A.
name: Bernet, R.
name: Bertolin, A.
name: Betti, F.
name: Bettler, M. -O.
name: van Beuzekom, M.
name: Bifani, S.
name: Billoir, P.
name: Bird, T.
name: Birnkraut, A.
name: Bizzeti, A.
name: Blake, T.
name: Blanc, F.
name: Blouw, J.
name: Blusk, S.
name: Bocci, V.
name: Bondar, A.
name: Bondar, N.
name: Bonivento, W.
name: Borgheresi, A.
name: Borghi, S.
name: Borisyak, M.
name: Borsato, M.
name: Bowcock, T. J. V.
name: Bowen, E.
name: Bozzi, C.
name: Braun, S.
name: Britsch, M.
name: Britton, T.
name: Brodzicka, J.
name: Brook, N. H.
name: Buchanan, E.
name: Burr, C.
name: Bursche, A.
name: Buytaert, J.
name: Cadeddu, S.
name: Calabrese, R.
name: Calvi, M.
name: Gomez, M. Calvo
name: Campana, P.
name: Perez, D. Campora
name: Capriotti, L.
name: Carbone, A.
name: Carboni, G.
name: Cardinale, R.
name: Cardini, A.
name: Carniti, P.
name: Carson, L.
name: Akiba, K. Carvalho
name: Casse, G.
name: Cassina, L.
name: Garcia, L. Castillo
name: Cattaneo, M.
name: Cauet, Ch.
name: Cavallero, G.
name: Cenci, R.
name: Charles, M.
name: Charpentier, Ph.
name: Chatzikonstantinidis, G.
name: Chefdeville, M.
name: Chen, S.
name: Cheung, S. -F.
name: Chiapolini, N.
name: Chrzaszcz, M.
name: Vidal, X. Cid
name: Ciezarek, G.
name: Clarke, P. E. L.
name: Clemencic, M.
name: Cliff, H. V.
name: Closier, J.
name: Coco, V.
name: Cogan, J.
name: Cogneras, E.
name: Cogoni, V.
name: Cojocariu, L.
name: Collazuol, G.
name: Collins, P.
name: Comerma-Montells, A.
name: Contu, A.
name: Cook, A.
name: Coombes, M.
name: Coquereau, S.
name: Corti, G.
name: Corvo, M.
name: Couturier, B.
name: Cowan, G. A.
name: Craik, D. C.
name: Crocombe, A.
name: Torres, M. Cruz
name: Cunliffe, S.
name: Currie, R.
name: D'Ambrosio, C.
name: Dall'Occo, E.
name: Dalseno, J.
name: David, P. N. Y.
name: Davis, A.
name: Francisco, O. De Aguiar
name: De Bruyn, K.
name: De Capua, S.
name: De Cian, M.
name: De Miranda, J. M.
name: De Paula, L.
name: De Simone, P.
name: Dean, C. -T.
name: Decamp, D.
name: Deckenhoff, M.
name: Del Buono, L.
name: Déléage, N.
name: Demmer, M.
name: Derkach, D.
name: Deschamps, O.
name: Dettori, F.
name: Dey, B.
name: Di Canto, A.
name: Di Ruscio, F.
name: Dijkstra, H.
name: Donleavy, S.
name: Dordei, F.
name: Dorigo, M.
name: Suárez, A. Dosil
name: Dovbnya, A.
name: Dreimanis, K.
name: Dufour, L.
name: Dujany, G.
name: Dungs, K.
name: Durante, P.
name: Dzhelyadin, R.
name: Dziurda, A.
name: Dzyuba, A.
name: Easo, S.
name: Egede, U.
name: Egorychev, V.
name: Eidelman, S.
name: Eisenhardt, S.
name: Eitschberger, U.
name: Ekelhof, R.
name: Eklund, L.
name: Rifai, I. El
name: Elsasser, Ch.
name: Ely, S.
name: Esen, S.
name: Evans, H. M.
name: Evans, T.
name: Falabella, A.
name: Färber, C.
name: Farley, N.
name: Farry, S.
name: Fay, R.
name: Fazzini, D.
name: Ferguson, D.
name: Albor, V. Fernandez
name: Ferrari, F.
name: Rodrigues, F. Ferreira
name: Ferro-Luzzi, M.
name: Filippov, S.
name: Fiore, M.
name: Fiorini, M.
name: Firlej, M.
name: Fitzpatrick, C.
name: Fiutowski, T.
name: Fleuret, F.
name: Fohl, K.
name: Fol, P.
name: Fontana, M.
name: Fontanelli, F.
name: Forshaw, D. C.
name: Forty, R.
name: Frank, M.
name: Frei, C.
name: Frosini, M.
name: Fu, J.
name: Furfaro, E.
name: Torreira, A. Gallas
name: Galli, D.
name: Gallorini, S.
name: Gambetta, S.
name: Gandelman, M.
name: Gandini, P.
name: Gao, Y.
name: Pardiñas, J. García
name: Tico, J. Garra
name: Garrido, L.
name: Gascon, D.
name: Gaspar, C.
name: Gavardi, L.
name: Gazzoni, G.
name: Gerick, D.
name: Gersabeck, E.
name: Gersabeck, M.
name: Gershon, T.
name: Ghez, Ph.
name: Gianì, S.
name: Gibson, V.
name: Girard, O. G.
name: Giubega, L.
name: Gligorov, V. V.
name: Göbel, C.
name: Golubkov, D.
name: Golutvin, A.
name: Gomes, A.
name: Gotti, C.
name: Gándara, M. Grabalosa
name: Diaz, R. Graciani
name: Cardoso, L. A. Granado
name: Graugés, E.
name: Graverini, E.
name: Graziani, G.
name: Grecu, A.
name: Griffith, P.
name: Grillo, L.
name: Grünberg, O.
name: Gui, B.
name: Gushchin, E.
name: Guz, Yu.
name: Gys, T.
name: Hadavizadeh, T.
name: Hadjivasiliou, C.
name: Haefeli, G.
name: Haen, C.
name: Haines, S. C.
name: Hall, S.
name: Hamilton, B.
name: Han, X.
name: Hansmann-Menzemer, S.
name: Harnew, N.
name: Harnew, S. T.
name: Harrison, J.
name: He, J.
name: Head, T.
name: Heijne, V.
name: Heister, A.
name: Hennessy, K.
name: Henrard, P.
name: Henry, L.
name: Morata, J. A. Hernando
name: van Herwijnen, E.
name: Heß, M.
name: Hicheur, A.
name: Hill, D.
name: Hoballah, M.
name: Hombach, C.
name: Hulsbergen, W.
name: Humair, T.
name: Hushchyn, M.
name: Hussain, N.
name: Hutchcroft, D.
name: Hynds, D.
name: Idzik, M.
name: Ilten, P.
name: Jacobsson, R.
name: Jaeger, A.
name: Jalocha, J.
name: Jans, E.
name: Jawahery, A.
name: John, M.
name: Johnson, D.
name: Jones, C. R.
name: Joram, C.
name: Jost, B.
name: Jurik, N.
name: Kandybei, S.
name: Kanso, W.
name: Karacson, M.
name: Karbach, T. M.
name: Karodia, S.
name: Kecke, M.
name: Kelsey, M.
name: Kenyon, I. R.
name: Kenzie, M.
name: Ketel, T.
name: Khairullin, E.
name: Khanji, B.
name: Khurewathanakul, C.
name: Kirn, T.
name: Klaver, S.
name: Klimaszewski, K.
name: Kochebina, O.
name: Kolpin, M.
name: Komarov, I.
name: Koopman, R. F.
name: Koppenburg, P.
name: Kozeiha, M.
name: Kravchuk, L.
name: Kreplin, K.
name: Kreps, M.
name: Krocker, G.
name: Krokovny, P.
name: Kruse, F.
name: Krzemien, W.
name: Kucewicz, W.
name: Kucharczyk, M.
name: Kudryavtsev, V.
name: Kuonen, A. K.
name: Kurek, K.
name: Kvaratskheliya, T.
name: Lacarrere, D.
name: Lafferty, G.
name: Lai, A.
name: Lambert, D.
name: Lanfranchi, G.
name: Langenbruch, C.
name: Langhans, B.
name: Latham, T.
name: Lazzeroni, C.
name: Gac, R. Le
name: van Leerdam, J.
name: Lees, J. -P.
name: Lefèvre, R.
name: Leflat, A.
name: Lefrançois, J.
name: Cid, E. Lemos
name: Leroy, O.
name: Lesiak, T.
name: Leverington, B.
name: Li, Y.
name: Likhomanenko, T.
name: Liles, M.
name: Lindner, R.
name: Linn, C.
name: Lionetto, F.
name: Liu, B.
name: Liu, X.
name: Loh, D.
name: Longstaff, I.
name: Lopes, J. H.
name: Lucchesi, D.
name: Martinez, M. Lucio
name: Luo, H.
name: Lupato, A.
name: Luppi, E.
name: Lupton, O.
name: Lusardi, N.
name: Lusiani, A.
name: Machefert, F.
name: Maciuc, F.
name: Maev, O.
name: Maguire, K.
name: Malde, S.
name: Malinin, A.
name: Manca, G.
name: Mancinelli, G.
name: Manning, P.
name: Mapelli, A.
name: Maratas, J.
name: Marchand, J. F.
name: Marconi, U.
name: Benito, C. Marin
name: Marino, P.
name: Marks, J.
name: Martellotti, G.
name: Martin, M.
name: Martinelli, M.
name: Santos, D. Martinez
name: Vidal, F. Martinez
name: Tostes, D. Martins
name: Massacrier, L. M.
name: Massafferri, A.
name: Matev, R.
name: Mathad, A.
name: Mathe, Z.
name: Matteuzzi, C.
name: Mauri, A.
name: Maurin, B.
name: Mazurov, A.
name: McCann, M.
name: McCarthy, J.
name: McNab, A.
name: McNulty, R.
name: Meadows, B.
name: Meier, F.
name: Meissner, M.
name: Melnychuk, D.
name: Merk, M.
name: Merli, A
name: Michielin, E
name: Milanes, D. A.
name: Minard, M. -N.
name: Mitzel, D. S.
name: Rodriguez, J. Molina
name: Monroy, I. A.
name: Monteil, S.
name: Morandin, M.
name: Morawski, P.
name: Mordà, A.
name: Morello, M. J.
name: Moron, J.
name: Morris, A. B.
name: Mountain, R.
name: Muheim, F.
name: Müller, D.
name: Müller, J.
name: Müller, K.
name: Müller, V.
name: Mussini, M.
name: Muster, B.
name: Naik, P.
name: Nakada, T.
name: Nandakumar, R.
name: Nandi, A.
name: Nasteva, I.
name: Needham, M.
name: Neri, N.
name: Neubert, S.
name: Neufeld, N.
name: Neuner, M.
name: Nguyen, A. D.
name: Nguyen-Mau, C.
name: Niess, V.
name: Nieswand, S.
name: Niet, R.
name: Nikitin, N.
name: Nikodem, T.
name: Novoselov, A.
name: O'Hanlon, D. P.
name: Oblakowska-Mucha, A.
name: Obraztsov, V.
name: Ogilvy, S.
name: Okhrimenko, O.
name: Oldeman, R.
name: Onderwater, C. J. G.
name: Rodrigues, B. Osorio
name: Goicochea, J. M. Otalora
name: Otto, A.
name: Owen, P.
name: Oyanguren, A.
name: Palano, A.
name: Palombo, F.
name: Palutan, M.
name: Panman, J.
name: Papanestis, A.
name: Pappagallo, M.
name: Pappalardo, L. L.
name: Pappenheimer, C.
name: Parker, W.
name: Parkes, C.
name: Passaleva, G.
name: Patel, G. D.
name: Patel, M.
name: Patrignani, C.
name: Pearce, A.
name: Pellegrino, A.
name: Penso, G.
name: Altarelli, M. Pepe
name: Perazzini, S.
name: Perret, P.
name: Pescatore, L.
name: Petridis, K.
name: Petrolini, A.
name: Petruzzo, M.
name: Olloqui, E. Picatoste
name: Pietrzyk, B.
name: Pikies, M.
name: Pinci, D.
name: Pistone, A.
name: Piucci, A.
name: Playfer, S.
name: Casasus, M. Plo
name: Poikela, T.
name: Polci, F.
name: Poluektov, A.
name: Polyakov, I.
name: Polycarpo, E.
name: Popov, A.
name: Popov, D.
name: Popovici, B.
name: Potterat, C.
name: Price, E.
name: Price, J. D.
name: Prisciandaro, J.
name: Pritchard, A.
name: Prouve, C.
name: Pugatch, V.
name: Navarro, A. Puig
name: Punzi, G.
name: Qian, W.
name: Quagliani, R.
name: Rachwal, B.
name: Rademacker, J. H.
name: Rama, M.
name: Pernas, M. Ramos
name: Rangel, M. S.
name: Raniuk, I.
name: Raven, G.
name: Redi, F.
name: Reichert, S.
name: Reis, A. C. dos
name: Renaudin, V.
name: Ricciardi, S.
name: Richards, S.
name: Rihl, M.
name: Rinnert, K.
name: Molina, V. Rives
name: Robbe, P.
name: Rodrigues, A. B.
name: Rodrigues, E.
name: Lopez, J. A. Rodriguez
name: Perez, P. Rodriguez
name: Rogozhnikov, A.
name: Roiser, S.
name: Romanovsky, V.
name: Vidal, A. Romero
name: Ronayne, J. W.
name: Rotondo, M.
name: Ruf, T.
name: Valls, P. Ruiz
name: Silva, J. J. Saborido
name: Sagidova, N.
name: Saitta, B.
name: Guimaraes, V. Salustino
name: Mayordomo, C. Sanchez
name: Sedes, B. Sanmartin
name: Santacesaria, R.
name: Rios, C. Santamarina
name: Santimaria, M.
name: Santovetti, E.
name: Sarti, A.
name: Satriano, C.
name: Satta, A.
name: Saunders, D. M.
name: Savrina, D.
name: Schael, S.
name: Schiller, M.
name: Schindler, H.
name: Schlupp, M.
name: Schmelling, M.
name: Schmelzer, T.
name: Schmidt, B.
name: Schneider, O.
name: Schopper, A.
name: Schubiger, M.
name: Schune, M. -H.
name: Schwemmer, R.
name: Sciascia, B.
name: Sciubba, A.
name: Semennikov, A.
name: Serra, N.
name: Serrano, J.
name: Sestini, L.
name: Seyfert, P.
name: Shapkin, M.
name: Shapoval, I.
name: Shcheglov, Y.
name: Shears, T.
name: Shekhtman, L.
name: Shevchenko, V.
name: Shires, A.
name: Siddi, B. G.
name: Coutinho, R. Silva
name: de Oliveira, L. Silva
name: Simi, G.
name: Sirendi, M.
name: Skidmore, N.
name: Skwarnicki, T.
name: Smith, E.
name: Smith, I. T.
name: Smith, J.
name: Smith, M.
name: Snoek, H.
name: Sokoloff, M. D.
name: Soler, F. J. P.
name: Soomro, F.
name: Souza, D.
name: De Paula, B. Souza
name: Spaan, B.
name: Spradlin, P.
name: Sridharan, S.
name: Stagni, F.
name: Stahl, M.
name: Stahl, S.
name: Stefkova, S.
name: Steinkamp, O.
name: Stenyakin, O.
name: Stevenson, S.
name: Stoica, S.
name: Stone, S.
name: Storaci, B.
name: Stracka, S.
name: Straticiuc, M.
name: Straumann, U.
name: Sun, L.
name: Sutcliffe, W.
name: Swientek, K.
name: Swientek, S.
name: Syropoulos, V.
name: Szczekowski, M.
name: Szumlak, T.
name: T'Jampens, S.
name: Tayduganov, A.
name: Tekampe, T.
name: Tellarini, G.
name: Teubert, F.
name: Thomas, C.
name: Thomas, E.
name: van Tilburg, J.
name: Tisserand, V.
name: Tobin, M.
name: Todd, J.
name: Tolk, S.
name: Tomassetti, L.
name: Tonelli, D.
name: Topp-Joergensen, S.
name: Tournefier, E.
name: Tourneur, S.
name: Trabelsi, K.
name: Traill, M.
name: Tran, M. T.
name: Tresch, M.
name: Trisovic, A.
name: Tsaregorodtsev, A.
name: Tsopelas, P.
name: Tuning, N.
name: Ukleja, A.
name: Ustyuzhanin, A.
name: Uwer, U.
name: Vacca, C.
name: Vagnoni, V.
name: Valenti, G.
name: Vallier, A.
name: Gomez, R. Vazquez
name: Regueiro, P. Vazquez
name: Sierra, C. Vázquez
name: Vecchi, S.
name: van Veghel, M.
name: Velthuis, J. J.
name: Veltri, M.
name: Veneziano, G.
name: Vesterinen, M.
name: Viaud, B.
name: Vieira, D.
name: Diaz, M. Vieites
name: Vilasis-Cardona, X.
name: Volkov, V.
name: Vollhardt, A.
name: Voong, D.
name: Vorobyev, A.
name: Vorobyev, V.
name: Voß, C.
name: de Vries, J. A.
name: Waldi, R.
name: Wallace, C.
name: Wallace, R.
name: Walsh, J.
name: Wang, J.
name: Ward, D. R.
name: Watson, N. K.
name: Websdale, D.
name: Weiden, A.
name: Whitehead, M.
name: Wicht, J.
name: Wilkinson, G.
name: Wilkinson, M.
name: Williams, M.
name: Williams, M. P.
name: Williams, M.
name: Williams, T.
name: Wilson, F. F.
name: Wimberley, J.
name: Wishahi, J.
name: Wislicki, W.
name: Witek, M.
name: Wormser, G.
name: Wotton, S. A.
name: Wraight, K.
name: Wright, S.
name: Wyllie, K.
name: Xie, Y.
name: Xu, Z.
name: Yang, Z.
name: Yu, J.
name: Yuan, X.
name: Yushchenko, O.
name: Zangoli, M.
name: Zavertyaev, M.
name: Zhang, L.
name: Zhang, Y.
name: Zhelezov, A.
name: Zhokhov, A.
name: Zhong, L.
name: Zhukov, V.
name: Zucchelli, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: A new algorithm for the determination of the initial flavour of $B_s^0$ mesons is presented. The algorithm is based on two neural networks and exploits the $b$ hadron production mechanism at a hadron collider. The first network is trained to select charged kaons produced in association with the $B_s^0$ meson. The second network combines the kaon charges to assign the $B_s^0$ flavour and estimates the probability of a wrong assignment. The algorithm is calibrated using data corresponding to an integrated luminosity of 3 fb$^{-1}$ collected by the LHCb experiment in proton-proton collisions at 7 and 8 TeV centre-of-mass energies. The calibration is performed in two ways: by resolving the $B_s^0$-$\bar{B}_s^0$ flavour oscillations in $B_s^0 \to D_s^- π^+$ decays, and by analysing flavour-specific $B_{s 2}^{*}(5840)^0 \to B^+ K^-$ decays. The tagging power measured in $B_s^0 \to D_s^- π^+$ decays is found to be $(1.80 \pm 0.19({\rm stat}) \pm 0.18({\rm syst}))$\%, which is an improvement of about 50\% compared to a similar algorithm previously used in the LHCb experiment.
description: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-056.html