Search for charged Higgs bosons in e+e− collisions at energies up to = 189 GeV

The data collected at centre-of-mass energies of 188.6 GeV by ALEPH at LEP, corresponding to an integrated luminosity of 176.2 pb−1, are analysed in a search for pair-produced charged Higgs bosons H±. Three analyses are employed to select the τνττ −ν̄τ , cs̄τ−ν̄τ and cs̄sc̄ final states. No evidence for a signal is found. Upper limits are set on the production cross section as a function of the branching fraction B(H→τντ ) and of the mass mH± , assuming that the sum of the branching ratios is equal to one. In the framework of a two-Higgs-doublet model, charged Higgs bosons with masses below 65.4 GeV/c2 are excluded at 95% confidence level independently of the decay mode. (Submitted to Physics Letters B) ——————————————– ∗) See next pages for the list of authors The ALEPH Collaboration R. Barate, D. Decamp, P. Ghez, C. Goy, S. Jezequel, J.-P. Lees, F. Martin, E. Merle, M.-N. Minard, B. Pietrzyk Laboratoire de Physique des Particules (LAPP), INP-CNRS, F-74019 Annecy-le-Vieux Cedex, France S. Bravo, M.P. Casado, M. Chmeissani, J.M. Crespo, E. Fernandez, M. Fernandez-Bosman, Ll. Garrido, E. Graugés, J. Lopez, M. Martinez, G. Merino, R. Miquel, Ll.M. Mir, A. Pacheco, D. Paneque, H. Ruiz Institut de Física d’Altes Energies, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain A. Colaleo, D. Creanza, N. De Filippis, M. de Palma, G. Iaselli, G. Maggi, M. Maggi, S. Nuzzo, A. Ranieri, G. Raso, F. Ruggieri, G. Selvaggi, L. Silvestris, P. Tempesta, A. Tricomi, G. Zito Dipartimento di Fisica, INFN Sezione di Bari, I-70126 Bari, Italy X. Huang, J. Lin, Q. Ouyang, T. Wang, Y. Xie, R. Xu, S. Xue, J. Zhang, L. Zhang, W. Zhao Institute of High Energy Physics, Academia Sinica, Beijing, The People’s Republic of China D. Abbaneo, G. Boix, O. Buchmüller, M. Cattaneo, F. Cerutti, G. Dissertori, H. Drevermann, R.W. Forty, M. Frank, F. Gianotti, T.C. Greening, A.W. Halley, J.B. Hansen, J. Harvey, P. Janot, B. Jost, M. Kado, V. Lemaitre, P. Maley, P. Mato, A. Minten, A. Moutoussi, F. Ranjard, L. Rolandi, D. Schlatter, M. Schmitt, O. Schneider, P. Spagnolo, W. Tejessy, F. Teubert, E. Tournefier, A. Valassi, J.J. Ward, A.E. Wright European Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland Z. Ajaltouni, F. Badaud, G. Chazelle, O. Deschamps, S. Dessagne, A. Falvard, P. Gay, C. Guicheney, P. Henrard, J. Jousset, B. Michel, S. Monteil, J-C. Montret, D. Pallin, J.M. Pascolo, P. Perret, F. Podlyski Laboratoire de Physique Corpusculaire, Université Blaise Pascal, INP-CNRS, Clermont-Ferrand, F-63177 Aubière, France J.D. Hansen, J.R. Hansen, P.H. Hansen, B.S. Nilsson, A. Wäänänen Niels Bohr Institute, 2100 Copenhagen, DK-Denmark G. Daskalakis, A. Kyriakis, C. Markou, E. Simopoulou, A. Vayaki Nuclear Research Center Demokritos (NRCD), GR-15310 Attiki, Greece A. Blondel, J.-C. Brient, F. Machefert, A. Rougé, M. Swynghedauw, R. Tanaka H. Videau Laboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, INP-CNRS, F-91128 Palaiseau Cedex, France E. Focardi, G. Parrini, K. Zachariadou Dipartimento di Fisica, Università di Firenze, INFN Sezione di Firenze, I-50125 Firenze, Italy A. Antonelli, M. Antonelli, G. Bencivenni, G. Bologna, F. Bossi, P. Campana, G. Capon, V. Chiarella, P. Laurelli, G. Mannocchi, F. Murtas, G.P. Murtas, L. Passalacqua, M. Pepe-Altarelli Laboratori Nazionali dell’INFN (LNF-INFN), I-00044 Frascati, Italy M. Chalmers, J. Kennedy, J.G. Lynch, P. Negus, V. O’Shea, B. Raeven, D. Smith, P. Teixeira-Dias, A.S. Thompson Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ,United Kingdom R. Cavanaugh, S. Dhamotharan, C. Geweniger, P. Hanke, V. Hepp, E.E. Kluge, G. Leibenguth, A. Putzer, K. Tittel, S. Werner, M. Wunsch Kirchhoff-Institut für Physik, Universität Heidelberg, D-69120 Heidelberg, Germany R. Beuselinck, D.M. Binnie, W. Cameron, G. Davies, P.J. Dornan, M. Girone, N. Marinelli, J. Nowell, H. Przysiezniak, J.K. Sedgbeer, J.C. Thompson, E. Thomson, R. White Department of Physics, Imperial College, London SW7 2BZ, United Kingdom V.M. Ghete, P. Girtler, E. Kneringer, D. Kuhn, G. Rudolph Institut für Experimentalphysik, Universität Innsbruck, A-6020 Innsbruck, Austria C.K. Bowdery, P.G. Buck, D.P. Clarke, G. Ellis, A.J. Finch, F. Foster, G. Hughes, R.W.L. Jones, N.A. Robertson, M. Smizanska Department of Physics, University of Lancaster, Lancaster LA1 4YB, United Kingdom I. Giehl, F. Hölldorfer, K. Jakobs, K. Kleinknecht, M. Kröcker, A.-S. Müller, H.-A. Nürnberger, G. Quast, B. Renk, E. Rohne, H.-G. Sander, S. Schmeling, H. Wachsmuth, C. Zeitnitz, T. Ziegler Institut für Physik, Universität Mainz, D-55099 Mainz, Germany A. Bonissent, J. Carr, P. Coyle, C. Curtil, A. Ealet, D. Fouchez, O. Leroy, T. Kachelhoffer, P. Payre, D. Rousseau, A. Tilquin Centre de Physique des Particules de Marseille, Univ Méditerranée, INP-CNRS, F-13288 Marseille, France M. Aleppo, S. Gilardoni, F. Ragusa Dipartimento di Fisica, Università di Milano e INFN Sezione di Milano, I-20133 Milano, Italy. H. Dietl, G. Ganis, A. Heister, K. Hüttmann, G. Lütjens, C. Mannert, W. Männer, H.-G. Moser, S. Schael, R. Settles, H. Stenzel, W. Wiedenmann, G. Wolf Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, D-80805 München, Germany P. Azzurri, J. Boucrot, O. Callot, M. Davier, L. Duflot, J.-F. Grivaz, Ph. Heusse, A. Jacholkowska, L. Serin, J.-J. Veillet, I. Videau, J.-B. de Vivie de Régie, D. Zerwas Laboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91898 Orsay Cedex, France G. Bagliesi, T. Boccali, G. Calderini, V. Ciulli, L. Foà, A. Giammanco, A. Giassi, F. Ligabue, A. Messineo, F. Palla, G. Rizzo, G. Sanguinetti, A. Sciabà, G. Sguazzoni, R. Tenchini, A. Venturi, P.G. Verdini Dipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, I-56010 Pisa, Italy G.A. Blair, J. Coles, G. Cowan, M.G. Green, D.E. Hutchcroft, L.T. Jones, T. Medcalf, J.A. Strong, J.H. von Wimmersperg-Toeller Department of Physics, Royal Holloway & Bedford New College, University of London, Surrey TW20 OEX, United Kingdom R.W. Clifft, T.R. Edgecock, P.R. Norton, I.R. Tomalin Particle Physics Dept., Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 OQX, United Kingdom B. Bloch-Devaux, D. Boumediene, P. Colas, B. Fabbro, G. Fäıf, E. Lançon, M.-C. Lemaire, E. Locci, P. Perez, J. Rander, J.-F. Renardy, A. Rosowsky, P. Seager, A. Trabelsi, B. Tuchming, B. Vallage CEA, DAPNIA/Service de Physique des Particules, CE-Saclay, F-91191 Gif-sur-Yvette Cedex, France S.N. Black, J.H. Dann, C. Loomis, H.Y. Kim, N. Konstantinidis, A.M. Litke, M.A. McNeil, G. Taylor Institute for Particle Physics, University of California at Santa Cruz, Santa Cruz, CA 95064, USA C.N. Booth, S. Cartwright, F. Combley, P.N. Hodgson, M. Lehto, L.F. Thompson Department of Physics, University of Sheffield, Sheffield S3 7RH, United Kingdom K. Affholderbach, A. Böhrer, S. Brandt, C. Grupen, J. Hess, A. Misiejuk, G. Prange, U. Sieler Fachbereich Physik, Universität Siegen, D-57068 Siegen, Germany C. Borean, G. Giannini, B. Gobbo Dipartimento di Fisica, Università di Trieste e INFN Sezione di Trieste, I-34127 Trieste, Italy H. He, J. Putz, J. Rothberg, S. Wasserbaech Experimental Elementary Particle Physics, University of Washington, Seattle, WA 98195 U.S.A. S.R. Armstrong, K. Cranmer, P. Elmer, D.P.S. Ferguson, Y. Gao, S. González, O.J. Hayes, H. Hu, S. Jin, J. Kile, P.A. McNamara III, J. Nielsen, W. Orejudos, Y.B. Pan, Y. Saadi, I.J. Scott, J. Walsh, J. Wu, Sau Lan Wu, X. Wu, G. Zobernig Department of Physics, University of Wisconsin, Madison, WI 53706, USA Also at CERN, 1211 Geneva 23, Switzerland. Now at Université de Lausanne, 1015 Lausanne, Switzerland. Also at Dipartimento di Fisica di Catania and INFN Sezione di Catania, 95129 Catania, Italy. Also Istituto di Fisica Generale, Università di Torino, 10125 Torino, Italy. Also Istituto di Cosmo-Geofisica del C.N.R., Torino, Italy. Supported by the Commission of the European Communities, contract ERBFMBICT982894. Supported by CICYT, Spain. Supported by the National Science Foundation of China. Supported by the Danish Natural Science Research Council. Supported by the UK Particle Physics and Astronomy Research Council. Supported by the US Department of Energy, grant DE-FG0295-ER40896. Now at Departement de Physique Corpusculaire, Université de Genève, 1211 Genève 4, Switzerland. Supported by the Commission of the European Communities, contract ERBFMBICT982874. Also at Rutherford Appleton Laboratory, Chilton, Didcot, UK. Permanent address: Universitat de Barcelona, 08208 Barcelona, Spain. Supported by the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie, Germany. Supported by the Direction des Sciences de la Matière, C.E.A. Supported by the Austrian Ministry for Science and Transport. Now at SAP AG, 69185 Walldorf, Germany Now at Harvard University, Cambridge, MA 02138, U.S.A. Now at Département de Physique, Faculté des Sciences de Tunis, 1060 Le Belvédère, Tunisia. Supported by the US Department of Energy, grant DE-FG03-92ER40689. Now at Department of Physics, Ohio State University, Columbus, OH 43210-1106, U.S.A.