1. Search for Single Top Quark Production in ep Collisions at HERA
- Author
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Aktas, A., Andreev, V., Anthonis, T., Asmone, A., Babaev, A., Backovic, S., Bahr, J., Baranov, P., Barrelet, E., Bartel, W., Baumgartner, S., Becker, J., Beckingham, M., Behnke, O., Behrendt, O., Belousov, A., Berger, C., Berndt, T., Bizot, J.C., Bohme, J., Boenig, M.O., Boudry, V., Bracinik, J., Braunschweig, W., Brisson, V., Broker, H.B., Brown, D.P., Bruncko, D., Busser, F.W., Bunyatyan, A., Buschhorn, G., Bystritskaya, L., Campbell, A.J., Caron, S., Cassol-Brunner, F., Chekelian, V., Clarke, D., Collard, C., Contreras, J.G., Coppens, Y.R., Coughlan, J.A., Cousinou, M.C., Cox, B.E., Cozzika, G., Cvach, J., Dainton, J.B., Dau, W.D., Daum, K., Delcourt, B., Delerue, N., Demirchyan, R., de Roeck, A., de Wolf, E.A., Diaconu, C., Dingfelder, J., Dodonov, V., Dowell, J.D., Dubak, A., Duprel, C., Eckerlin, G., Efremenko, V., Egli, S., Eichler, R., Eisele, F., Ellerbrock, M., Elsen, E., Erdmann, M., Erdmann, W., Faulkner, P.J.W., Favart, L., Fedotov, A., Felst, R., Ferencei, J., Fleischer, M., Fleischmann, P., Fleming, Y.H., Flucke, G., Flugge, G., Fomenko, A., Foresti, I., Formanek, J., Franke, G., Frising, G., Gabathuler, E., Gabathuler, K., Garvey, J., Gassner, J., Gayler, Joerg., Gerhards, R., Gerlich, C., Ghazaryan, S., Goerlich, L., Gogitidze, N., Gorbounov, S., Grab, C., Grabski, V., Grassler, H., Greenshaw, T., Gregori, M., Grindhammer, G., Haidt, D., Hajduk, L., Haller, J., Heinzelmann, G., Henderson, R.C.W., Henschel, H., Henshaw, O., Heremans, R., Herrera, G., Herynek, I., Hildebrandt, M., Hiller, K.H., Hladky, J., Hoting, P., Hoffmann, D., Horisberger, R., Hovhannisyan, A., Ibbotson, M., Jacquet, M., Janauschek, L., Janssen, X., Jemanov, V., Jonsson, L., Johnson, C., Johnson, D.P., Jung, H., Kant, D., Kapichine, M., Karlsson, M., Katzy, J., Keil, F., Keller, N., Kennedy, J., Kenyon, I.R., Kiesling, C., Klein, M., Kleinwort, C., Kluge, T., Knies, G., Koblitz, B., Kolya, S.D., Korbel, V., Kostka, P., Koutouev, R., Kropivnitskaya, A., Kroseberg, J., Kueckens, J., Kuhr, T., Landon, M.P.J., Lange, W., Lastovicka, T., Laycock, P., Lebedev, A., Leissner, B., Lemrani, R., Lendermann, V., Levonian, S., List, B., Lobodzinska, E., Loktionova, N., Lopez-Fernandez, R., Lubimov, V., Lueders, H., Luders, S., Luke, D., Lytkin, L., Makankine, A., Malden, N., Malinovski, E., Mangano, S., Marage, P., Marks, J., Marshall, R., Martyn, H.U., Martyniak, J., Maxfield, S.J., Meer, D., Mehta, A., Meier, K., Meyer, A.B., Meyer, H., Meyer, J., Michine, S., Mikocki, S., Milstead, D., Moreau, F., Morozov, A., Morozov, I., Morris, J.V., Muller, K., Murin, P., Nagovizin, V., Naroska, B., Naumann, J., Naumann, T., Newman, P.R., Niebergall, F., Niebuhr, C., Nikitin, D., Nowak, G., Nozicka, M., Olivier, B., Olsson, J.E., Ossoskov, G., Ozerov, D., Pascaud, C., Patel, G.D., Peez, M., Perez, Emile, Petrukhin, A., Pitzl, D., Poschl, R., Povh, B., Raicevic, N., Rauschenberger, J., Reimer, P., Reisert, B., Risler, C., Rizvi, E., Robmann, P., Roosen, R., Rostovtsev, A., Rusakov, S., Rybicki, K., Sankey, D.P.C., Sauvan, E., Schatzel, S., Scheins, J., Schilling, F.P., Schleper, P., Schmidt, S., Schmitt, S., Schneider, M., Schoeffel, L., Schoning, A., Schroder, V., Schultz-Coulon, H.C., Schwanenberger, C., Sedlak, K., Sefkow, F., Sheviakov, I., Shtarkov, L.N., Sirois, Y., Sloan, T., Smirnov, P., Soloviev, Y., South, D., Spaskov, V., Specka, A., Spitzer, H., Stamen, R., Stella, B., Stiewe, J., Strauch, I., Straumann, U., Thompson, G., Thompson, P.D., Tomasz, F., Traynor, D., Truol, P., Tsipolitis, G., Tsurin, I., Turnau, J., Turney, J.E., Tzamariudaki, E., Uraev, A., Urban, Martin, Usik, A., Valkar, S., Valkarova, A., Vallee, C., van Mechelen, P., Vargas Trevino, A., Vassiliev, S., Vazdik, Y., Veelken, C., Vest, A., Vichnevski, A., Vinokurova, S., Volchinski, V., Wacker, K., Wagner, J., Waugh, B., Weber, G., Weber, R., Wegener, D., Werner, C., Werner, N., Wessels, M., Wessling, B., Winde, M., Winter, G.G., Wissing, C., Woehrling, E.E., Wunsch, E., Zacek, J., Zalesak, J., Zhang, Zhiqing, Zhokin, A., Zomer, F., Zur Nedden, M., Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), H1, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and H1 Collaboration
- Subjects
Quark ,Physics ,Particle physics ,Top quark ,Physics and Astronomy (miscellaneous) ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Top quark condensate ,HERA ,Omega baryon ,Bottom quark ,Standard Model ,Sigma baryon ,High Energy Physics - Experiment ,Nuclear physics ,High Energy Physics - Experiment (hep-ex) ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,High Energy Physics::Experiment ,Engineering (miscellaneous) - Abstract
A search for single top quark production is performed in e±p collisions at HERA. The search exploits data corresponding to an integrated luminosity of 118.3 pb-1. A model for the anomalous production of top quarks in a flavour changing neutral current process involving a tuγ coupling is investigated. Decays of top quarks into a b quark and a W boson are considered in the leptonic and the hadronic decay channels of the W. Both a cut-based analysis and a multivariate likelihood analysis are performed to discriminate anomalous top quark production from Standard Model background processes. In the leptonic channel, 5 events are found while 1.31 ± 0.22 events are expected from the Standard Model background. In the hadronic channel, no excess above the expectation for Standard Model processes is found. These observations lead to a cross section σ(ep→etX)=0.29+0.15−0.14 pb at s√=319 GeV. Alternatively, assuming that the observed events are due to a statistical fluctuation, upper limits of 0.55 pb on the anomalous top production cross section and of 0.27 on the tuγ coupling κtuγ are established at the 95% confidence level., The European Physical Journal C, 33 (1), ISSN:1434-6044, ISSN:1434-6052
- Published
- 2004