학술논문

First observation of forward $Z \rightarrow b \bar{b}$ production in $pp$ collisions at $\sqrt{s}=8$ TeV
Document Type
Working Paper
Author
LHCb collaborationAaij, R.Adeva, B.Adinolfi, M.Ajaltouni, Z.Akar, S.Albrecht, J.Alessio, F.Alexander, M.Albero, A. AlfonsoAli, S.Alkhazov, G.Cartelle, P. AlvarezAlves Jr, A. A.Amato, S.Amerio, S.Amhis, Y.An, L.Anderlini, L.Andreassi, G.Andreotti, M.Andrews, J. E.Appleby, R. B.Archilli, F.d'Argent, P.Romeu, J. ArnauArtamonov, A.Artuso, M.Aslanides, E.Auriemma, G.Baalouch, M.Babuschkin, I.Bachmann, S.Back, J. J.Badalov, A.Baesso, C.Baker, S.Balagura, V.Baldini, W.Baranov, A.Barlow, R. J.Barschel, C.Barsuk, S.Barter, W.Baryshnikov, F.Batozskaya, V.Battista, V.Bay, A.Beaucourt, L.Beddow, J.Bedeschi, F.Bediaga, I.Beiter, A.Bel, L. J.Beliy, N.Bellee, V.Belloli, N.Belous, K.Belyaev, I.Ben-Haim, E.Bencivenni, G.Benson, S.Beranek, S.Berezhnoy, A.Bernet, R.Berninghoff, D.Bertholet, E.Bertolin, A.Betancourt, C.Betti, F.Bettler, M. -O.van Beuzekom, M.Bezshyiko, Ia.Bifani, S.Billoir, P.Birnkraut, A.Bitadze, A.Bizzeti, A.Bjørn, M.Blake, T.Blanc, F.Blouw, J.Blusk, S.Bocci, V.Boettcher, T.Bondar, A.Bondar, N.Bonivento, W.Bordyuzhin, I.Borgheresi, A.Borghi, S.Borisyak, M.Borsato, M.Bossu, F.Boubdir, M.Bowcock, T. J. V.Bowen, E.Bozzi, C.Braun, S.Britton, T.Brodzicka, J.Brundu, D.Buchanan, E.Burr, C.Bursche, A.Buytaert, J.Byczynski, W.Cadeddu, S.Cai, H.Calabrese, R.Calladine, R.Calvi, M.Gomez, M. CalvoCamboni, A.Campana, P.Perez, D. H. CamporaCapriotti, L.Carbone, A.Carboni, G.Cardinale, R.Cardini, A.Carniti, P.Carson, L.Akiba, K. CarvalhoCasse, G.Cassina, L.Garcia, L. CastilloCattaneo, M.Cavallero, G.Cenci, R.Chamont, D.Chapman, M. G.Charles, M.Charpentier, Ph.Chatzikonstantinidis, G.Chefdeville, M.Chen, S.Cheung, S. F.Chitic, S. -G.Chobanova, V.Chrzaszcz, M.Chubykin, A.Ciambrone, P.Vidal, X. CidCiezarek, G.Clarke, P. E. L.Clemencic, M.Cliff, H. V.Closier, J.Cogan, J.Cogneras, E.Cogoni, V.Cojocariu, L.Collins, P.Colombo, T.Comerma-Montells, A.Contu, A.Cook, A.Coombs, G.Coquereau, S.Corti, G.Corvo, M.Sobral, C. M. CostaCouturier, B.Cowan, G. A.Craik, D. C.Crocombe, A.Torres, M. CruzCurrie, R.D'Ambrosio, C.Marinho, F. Da CunhaDall'Occo, E.Dalseno, J.Davis, A.Francisco, O. De AguiarDe Capua, S.De Cian, M.De Miranda, J. M.De Paula, L.De Serio, M.De Simone, P.Dean, C. T.Decamp, D.Del Buono, L.Dembinski, H. -P.Demmer, M.Dendek, A.Derkach, D.Deschamps, O.Dettori, F.Dey, B.Di Canto, A.Di Nezza, P.Dijkstra, H.Dordei, F.Dorigo, M.Suárez, A. DosilDouglas, L.Dovbnya, A.Dreimanis, K.Dufour, L.Dujany, G.Durante, P.Dzhelyadin, R.Dziewiecki, M.Dziurda, A.Dzyuba, A.Easo, S.Ebert, M.Egede, U.Egorychev, V.Eidelman, S.Eisenhardt, S.Eitschberger, U.Ekelhof, R.Eklund, L.Ely, S.Esen, S.Evans, H. M.Evans, T.Falabella, A.Farley, N.Farry, S.Fazzini, D.Federici, L.Ferguson, D.Fernandez, G.Declara, P. FernandezPrieto, A. FernandezFerrari, F.Rodrigues, F. FerreiraFerro-Luzzi, M.Filippov, S.Fini, R. A.Fiore, M.Fiorini, M.Firlej, M.Fitzpatrick, C.Fiutowski, T.Fleuret, F.Fohl, K.Fontana, M.Fontanelli, F.Forshaw, D. C.Forty, R.Lima, V. FrancoFrank, M.Frei, C.Fu, J.Funk, W.Furfaro, E.Färber, C.Gabriel, E.Torreira, A. GallasGalli, D.Gallorini, S.Gambetta, S.Gandelman, M.Gandini, P.Gao, Y.Martin, L. M. GarciaPardiñas, J. GarcíaTico, J. GarraGarrido, L.Garsed, P. J.Gascon, D.Gaspar, C.Gavardi, L.Gazzoni, G.Gerick, D.Gersabeck, E.Gersabeck, M.Gershon, T.Ghez, Ph.Gianì, S.Gibson, V.Girard, O. G.Giubega, L.Gizdov, K.Gligorov, V. V.Golubkov, D.Golutvin, A.Gomes, A.Gorelov, I. V.Gotti, C.Govorkova, E.Grabowski, J. P.Diaz, R. GracianiCardoso, L. A. GranadoGraugés, E.Graverini, E.Graziani, G.Grecu, A.Greim, R.Griffith, P.Grillo, L.Gruber, L.Cazon, B. R. GrubergGrünberg, O.Gushchin, E.Guz, Yu.Gys, T.Göbel, C.Hadavizadeh, T.Hadjivasiliou, C.Haefeli, G.Haen, C.Haines, S. C.Hamilton, B.Han, X.Hancock, T. H.Hansmann-Menzemer, S.Harnew, N.Harnew, S. T.Harrison, J.Hasse, C.Hatch, M.He, J.Hecker, M.Heinicke, K.Heister, A.Hennessy, K.Henrard, P.Henry, L.van Herwijnen, E.Heß, M.Hicheur, A.Hill, D.Hombach, C.Hopchev, P. H.Huard, Z. C.Hulsbergen, W.Humair, T.Hushchyn, M.Hutchcroft, D.Ibis, P.Idzik, M.Ilten, P.Jacobsson, R.Jalocha, J.Jans, E.Jawahery, A.Jiang, F.John, M.Johnson, D.Jones, C. R.Joram, C.Jost, B.Jurik, N.Kandybei, S.Karacson, M.Kariuki, J. M.Karodia, S.Kazeev, N.Kecke, M.Kelsey, M.Kenzie, M.Ketel, T.Khairullin, E.Khanji, B.Khurewathanakul, C.Kirn, T.Klaver, S.Klimaszewski, K.Klimkovich, T.Koliiev, S.Kolpin, M.Komarov, I.Kopecna, R.Koppenburg, P.Kosmyntseva, A.Kotriakhova, S.Kozeiha, M.Kravchuk, L.Kreps, M.Krokovny, P.Kruse, F.Krzemien, W.Kucewicz, W.Kucharczyk, M.Kudryavtsev, V.Kuonen, A. K.Kurek, K.Kvaratskheliya, T.Lacarrere, D.Lafferty, G.Lai, A.Lanfranchi, G.Langenbruch, C.Latham, T.Lazzeroni, C.Gac, R. LeLeflat, A.Lefrançois, J.Lefèvre, R.Lemaitre, F.Cid, E. LemosLeroy, O.Lesiak, T.Leverington, B.Li, P. -R.Li, T.Li, Y.Li, Z.Likhomanenko, T.Lindner, R.Lionetto, F.Lisovskyi, V.Liu, X.Loh, D.Loi, A.Longstaff, I.Lopes, J. H.Lucchesi, D.Martinez, M. LucioLuo, H.Lupato, A.Luppi, E.Lupton, O.Lusiani, A.Lyu, X.Machefert, F.Maciuc, F.Macko, V.Mackowiak, P.Maddrell-Mander, S.Maev, O.Maguire, K.Maisuzenko, D.Majewski, M. W.Malde, S.Malinin, A.Maltsev, T.Manca, G.Mancinelli, G.Manning, P.Marangotto, D.Maratas, J.Marchand, J. F.Marconi, U.Benito, C. MarinMarinangeli, M.Marino, P.Marks, J.Martellotti, G.Martin, M.Martinelli, M.Santos, D. MartinezVidal, F. MartinezTostes, D. MartinsMassacrier, L. M.Massafferri, A.Matev, R.Mathad, A.Mathe, Z.Matteuzzi, C.Mauri, A.Maurice, E.Maurin, B.Mazurov, A.McCann, M.McNab, A.McNulty, R.Mead, J. V.Meadows, B.Meaux, C.Meier, F.Meinert, N.Melnychuk, D.Merk, M.Merli, A.Michielin, E.Milanes, D. A.Millard, E.Minard, M. -N.Minzoni, L.Mitzel, D. S.Mogini, A.Rodriguez, J. MolinaMombächer, T.Monroy, I. A.Monteil, S.Morandin, M.Morello, M. J.Morgunova, O.Moron, J.Morris, A. B.Mountain, R.Muheim, F.Mulder, M.Müller, D.Müller, J.Müller, K.Müller, V.Naik, P.Nakada, T.Nandakumar, R.Nandi, A.Nasteva, I.Needham, M.Neri, N.Neubert, S.Neufeld, N.Neuner, M.Nguyen, T. D.Nguyen-Mau, C.Nieswand, S.Niet, R.Nikitin, N.Nikodem, T.Nogay, A.O'Hanlon, D. P.Oblakowska-Mucha, A.Obraztsov, V.Ogilvy, S.Oldeman, R.Onderwater, C. J. G.Ossowska, A.Goicochea, J. M. OtaloraOwen, P.Oyanguren, A.Pais, P. R.Palano, A.Palutan, M.Papanestis, A.Pappagallo, M.Pappalardo, L. L.Parker, W.Parkes, C.Passaleva, G.Pastore, A.Patel, M.Patrignani, C.Pearce, A.Pellegrino, A.Penso, G.Altarelli, M. PepePerazzini, S.Perret, P.Pescatore, L.Petridis, K.Petrolini, A.Petrov, A.Petruzzo, M.Olloqui, E. PicatostePietrzyk, B.Pikies, M.Pinci, D.Pisani, F.Pistone, A.Piucci, A.Placinta, V.Playfer, S.Casasus, M. PloPolci, F.Lener, M. PoliPoluektov, A.Polyakov, I.Polycarpo, E.Pomery, G. J.Ponce, S.Popov, A.Popov, D.Poslavskii, S.Potterat, C.Price, E.Prisciandaro, J.Prouve, C.Pugatch, V.Navarro, A. PuigPullen, H.Punzi, G.Qian, W.Quagliani, R.Quintana, B.Rachwal, B.Rademacker, J. H.Rama, M.Pernas, M. RamosRangel, M. S.Raniuk, I.Ratnikov, F.Raven, G.Salzgeber, M. RavonelReboud, M.Redi, F.Reichert, S.Reis, A. C. dosAlepuz, C. RemonRenaudin, V.Ricciardi, S.Richards, S.Rihl, M.Rinnert, K.Molina, V. RivesRobbe, P.Robert, A.Rodrigues, A. B.Rodrigues, E.Lopez, J. A. RodriguezPerez, P. RodriguezRogozhnikov, A.Roiser, S.Rollings, A.Romanovskiy, V.Vidal, A. RomeroRonayne, J. W.Rotondo, M.Rudolph, M. S.Ruf, T.Valls, P. RuizVidal, J. RuizSilva, J. J. SaboridoSadykhov, E.Sagidova, N.Saitta, B.Guimaraes, V. SalustinoMayordomo, C. SanchezSedes, B. SanmartinSantacesaria, R.Rios, C. SantamarinaSantimaria, M.Santovetti, E.Sarpis, G.Sarti, A.Satriano, C.Satta, A.Saunders, D. M.Savrina, D.Schael, S.Schellenberg, M.Schiller, M.Schindler, H.Schlupp, M.Schmelling, M.Schmelzer, T.Schmidt, B.Schneider, O.Schopper, A.Schreiner, H. F.Schubert, K.Schubiger, M.Schune, M. -H.Schwemmer, R.Sciascia, B.Sciubba, A.Semennikov, A.Sepulveda, E. S.Sergi, A.Serra, N.Serrano, J.Sestini, L.Seyfert, P.Shapkin, M.Shapoval, I.Shcheglov, Y.Shears, T.Shekhtman, L.Shevchenko, V.Siddi, B. G.Coutinho, R. Silvade Oliveira, L. SilvaSimi, G.Simone, S.Sirendi, M.Skidmore, N.Skwarnicki, T.Smith, E.Smith, I. T.Smith, J.Smith, M.Lavra, l. SoaresSokoloff, M. D.Soler, F. J. P.De Paula, B. SouzaSpaan, B.Spradlin, P.Sridharan, S.Stagni, F.Stahl, M.Stahl, S.Stefko, P.Stefkova, S.Steinkamp, O.Stemmle, S.Stenyakin, O.Stepanova, M.Stevens, H.Stone, S.Storaci, B.Stracka, S.Stramaglia, M. E.Straticiuc, M.Straumann, U.Sun, J.Sun, L.Sutcliffe, W.Swientek, K.Syropoulos, V.Szczekowski, M.Szumlak, T.Szymanski, M.T'Jampens, S.Tayduganov, A.Tekampe, T.Tellarini, G.Teubert, F.Thomas, E.van Tilburg, J.Tilley, M. J.Tisserand, V.Tobin, M.Tolk, S.Tomassetti, L.Tonelli, D.Toriello, F.Aoude, R. Tourinho JadallahTournefier, E.Traill, M.Tran, M. T.Tresch, M.Trisovic, A.Tsaregorodtsev, A.Tsopelas, P.Tully, A.Tuning, N.Ukleja, A.Usachov, A.Ustyuzhanin, A.Uwer, U.Vacca, C.Vagner, A.Vagnoni, V.Valassi, A.Valat, S.Valenti, G.Gomez, R. VazquezRegueiro, P. VazquezVecchi, S.van Veghel, M.Velthuis, J. J.Veltri, M.Veneziano, G.Venkateswaran, A.Verlage, T. A.Vernet, M.Vesterinen, M.Barbosa, J. V. VianaViaud, B.Vieira, D.Diaz, M. VieitesViemann, H.Vilasis-Cardona, X.Vitti, M.Volkov, V.Vollhardt, A.Voneki, B.Vorobyev, A.Vorobyev, V.Voß, C.de Vries, J. A.Sierra, C. VázquezWaldi, R.Wallace, C.Wallace, R.Walsh, J.Wang, J.Ward, D. R.Wark, H. M.Watson, N. K.Websdale, D.Weiden, A.Whitehead, M.Wicht, J.Wilkinson, G.Wilkinson, M.Williams, M.Williams, M. P.Williams, T.Wilson, F. F.Wimberley, J.Winn, M.Wishahi, J.Wislicki, W.Witek, M.Wormser, G.Wotton, S. A.Wraight, K.Wyllie, K.Xie, Y.Xu, Z.Yang, Z.Yao, Y.Yin, H.Yu, J.Yuan, X.Yushchenko, O.Zarebski, K. A.Zavertyaev, M.Zhang, L.Zhang, Y.Zhelezov, A.Zheng, Y.Zhu, X.Zhukov, V.Zonneveld, J. B.Zucchelli, S.
Source
Phys. Lett. B776 (2017) 430-439
Subject
High Energy Physics - Experiment
Language
Abstract
The decay $Z \rightarrow b \bar{b}$ is reconstructed in $pp$ collision data, corresponding to 2 fb$^{-1}$ of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of $\sqrt{s}=8$ TeV. The product of the $Z$ production cross-section and the $Z \rightarrow b \bar{b}$ branching fraction is measured for candidates in the fiducial region defined by two particle-level $b$-quark jets with pseudorapidities in the range $2.2 < \eta < 4.2$, with transverse momenta $p_{T}>20$ GeV and dijet invariant mass in the range $45 < m_{jj} < 165$ GeV. From a signal yield of $5462 \pm 763$ $Z \rightarrow b \bar{b}$ events, where the uncertainty is statistical, a production cross-section times branching fraction of $332 \pm 46 \pm 59$ pb is obtained, where the first uncertainty is statistical and the second systematic. The measured significance of the signal yield is 6.0 standard deviations. This measurement represents the first observation of the $Z \rightarrow b \bar{b}$ production in the forward region of $pp$ collisions.
Comment: 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-2017-024.html