Search for Higgs bosons decaying to WW in e+e- collisions at LEP

S. Schael; R. Barate; R. Brunelière; I. De Bonis; D. Decamp; C. Goy; S. Jézéquel; J.-P. Lees; F. Martin; E. Merle; M.-N. Minard; B. Pietrzyk; B. Trocmé; S. Bravo; M.P. Casado; M. Chmeissani; J.M. Crespo; E. Fernandez; M. Fernandez-Bosman; L. Garrido; M. Martinez; A. Pacheco; H. Ruiz; 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; X. Huang; J. Lin; Q. Ouyang; T. Wang; Y. Xie; R. Xu; S. Xue; J. Zhang; L. Zhang; W. Zhao; D. Abbaneo; T. Barklow; O. Buchmüller; M. Cattaneo; B. Clerbaux; H. Drevermann; R.W. Forty; M. Frank; F. Gianotti; J.B. Hansen; J. Harvey; D.E. Hutchcroft; P. Janot; B. Jost; M. Kado; P. Mato; A. Moutoussi; F. Ranjard; L. Rolandi; D. Schlatter; F. Teubert; A. Valassi; I. Videau; F. Badaud; S. Dessagne; A. Falvard; D. Fayolle; P. Gay; J. Jousset; B. Michel; S. Monteil; D. Pallin; J.M. Pascolo; P. Perret; J.D. Hansen; J.R. Hansen; P.H. Hansen; A.C. Kraan; B.S. Nilsson; A. Kyriakis; C. Markou; E. Simopoulou; A. Vayaki; K. Zachariadou; A. Blondel; J.-C. Brient; F. Machefert; A. Rougé; H. Videau; V. Ciulli; E. Focardi; G. Parrini; A. Antonelli; M. Antonelli; G. Bencivenni; F. Bossi; G. Capon; F. Cerutti; V. Chiarella; P. Laurelli; G. Mannocchi; G.P. Murtas; L. Passalacqua; J. Kennedy; J.G. Lynch; P. Negus; V. O’Shea; A.S. Thompson; S. Wasserbaech; R. Cavanaugh; S. Dhamotharan; C. Geweniger; P. Hanke; V. Hepp; E.E. Kluge; A. Putzer; H. Stenzel; K. Tittel; M. Wunsch; R. Beuselinck; W. Cameron; G. Davies; P.J. Dornan; M. Girone; N. Marinelli; J. Nowell; S.A. Rutherford; J.K. Sedgbeer; J.C. Thompson; R. White; V.M. Ghete; P. Girtler; E. Kneringer; D. Kuhn; G. Rudolph; E. Bouhova-Thacker; C.K. Bowdery; D.P. Clarke; G. Ellis; A.J. Finch; F. Foster; G. Hughes; R.W.L. Jones; M.R. Pearson; N.A. Robertson; M. Smizanska; O. van der Aa; C. Delaere; G. Leibenguth; V. Lemaitre; U. Blumenschein; F. Hölldorfer; K. Jakobs; F. Kayser; A.-S. Müller; B. Renk; H.-G. Sander; S. Schmeling; H. Wachsmuth; C. Zeitnitz; T. Ziegler; A. Bonissent; P. Coyle; C. Curtil; A. Ealet; D. Fouchez; P. Payre; A. Tilquin; F. Ragusa; A. David; H. Dietl; G. Ganis; K. Hüttmann; G. Lütjens; W. Männer; H.-G. Moser; R. Settles; M. Villegas; G. Wolf; J. Boucrot; O. Callot; M. Davier; L. Duflot; J.-F. Grivaz; P. Heusse; A. Jacholkowska; L. Serin; J.-J. Veillet; P. Azzurri; G. Bagliesi; T. Boccali; L. Foà; A. Giammanco; A. Giassi; F. Ligabue; A. Messineo; F. Palla; G. Sanguinetti; A. Sciabà; G. Sguazzoni; P. Spagnolo; R. Tenchini; A. Venturi; P.G. Verdini; O. Awunor; G.A. Blair; G. Cowan; A. Garcia-Bellido; M.G. Green; T. Medcalf; A. Misiejuk; J.A. Strong; P. Teixeira-Dias; R.W. Clifft; T.R. Edgecock; P.R. Norton; I.R. Tomalin; J.J. Ward; B. Bloch-Devaux; D. Boumediene; P. Colas; B. Fabbro; E. Lançon; M.-C. Lemaire; E. Locci; P. Perez; J. Rander; B. Tuchming; B. Vallage; A.M. Litke; G. Taylor; C.N. Booth; S. Cartwright; F. Combley; P.N. Hodgson; M. Lehto; L.F. Thompson; A. Böhrer; S. Brandt; C. Grupen; J. Hess; A. Ngac; G. Prange; C. Borean; G. Giannini; H. He; J. Putz; J. Rothberg; S.R. Armstrong; K. Berkelman; K. Cranmer; D.P.S. Ferguson; Y. Gao; S. González; O.J. Hayes; H. Hu; S. Jin; J. Kile; P.A. McNamara III; J. Nielsen; Y.B. Pan; J.H. von Wimmersperg-Toeller; W. Wiedenmann; J. Wu; Sau Lan Wu; X. Wu; G. Zobernig; G. Dissertori

doi:10.1140/epjc/s10052-006-0158-6

2023 Impact factor 4.2

Particles and Fields

Eur. Phys. J. C (2007) 49: 439-455
https://doi.org/10.1140/epjc/s10052-006-0158-6

Regular Article - Experimental Physics

Search for Higgs bosons decaying to WW in e⁺e^- collisions at LEP

S. Schael¹, R. Barate², R. Brunelière², I. De Bonis², D. Decamp², C. Goy², S. Jézéquel², J.-P. Lees², F. Martin², E. Merle², M.-N. Minard², B. Pietrzyk², B. Trocmé², S. Bravo³, M.P. Casado³, M. Chmeissani³, J.M. Crespo³, E. Fernandez³, M. Fernandez-Bosman³, L. Garrido³, M. Martinez³, A. Pacheco³, H. Ruiz³, A. Colaleo⁴, D. Creanza⁴, N. De Filippis⁴, M. De Palma⁴, G. Iaselli⁴, G. Maggi⁴, M. Maggi⁴, S. Nuzzo⁴, A. Ranieri⁴, G. Raso⁴, F. Ruggieri⁴, G. Selvaggi⁴, L. Silvestris⁴, P. Tempesta⁴, A. Tricomi⁴, G. Zito⁴, X. Huang⁵, J. Lin⁵, Q. Ouyang⁵, T. Wang⁵, Y. Xie⁵, R. Xu⁵, S. Xue⁵, J. Zhang⁵, L. Zhang⁵, W. Zhao⁵, D. Abbaneo⁶, T. Barklow⁶, O. Buchmüller⁶, M. Cattaneo⁶, B. Clerbaux⁶, H. Drevermann⁶, R.W. Forty⁶, M. Frank⁶, F. Gianotti⁶, J.B. Hansen⁶, J. Harvey⁶, D.E. Hutchcroft⁶, P. Janot⁶, B. Jost⁶, M. Kado⁶, P. Mato⁶, A. Moutoussi⁶, F. Ranjard⁶, L. Rolandi⁶, D. Schlatter⁶, F. Teubert⁶, A. Valassi⁶, I. Videau⁶, F. Badaud⁷, S. Dessagne⁷, A. Falvard⁷, D. Fayolle⁷, P. Gay⁷, J. Jousset⁷, B. Michel⁷, S. Monteil⁷, D. Pallin⁷, J.M. Pascolo⁷, P. Perret⁷, J.D. Hansen⁸, J.R. Hansen⁸, P.H. Hansen⁸, A.C. Kraan⁸, B.S. Nilsson⁸, A. Kyriakis⁹, C. Markou⁹, E. Simopoulou⁹, A. Vayaki⁹, K. Zachariadou⁹, A. Blondel¹⁰, J.-C. Brient¹⁰, F. Machefert¹⁰, A. Rougé¹⁰, H. Videau¹⁰, V. Ciulli¹¹, E. Focardi¹¹, G. Parrini¹¹, A. Antonelli¹², M. Antonelli¹², G. Bencivenni¹², F. Bossi¹², G. Capon¹², F. Cerutti¹², V. Chiarella¹², P. Laurelli¹², G. Mannocchi¹², G.P. Murtas¹², L. Passalacqua¹², J. Kennedy¹³, J.G. Lynch¹³, P. Negus¹³, V. O’Shea¹³, A.S. Thompson¹³, S. Wasserbaech¹⁴, R. Cavanaugh¹⁵, S. Dhamotharan¹⁵, C. Geweniger¹⁵, P. Hanke¹⁵, V. Hepp¹⁵, E.E. Kluge¹⁵, A. Putzer¹⁵, H. Stenzel¹⁵, K. Tittel¹⁵, M. Wunsch¹⁵, R. Beuselinck¹⁶, W. Cameron¹⁶, G. Davies¹⁶, P.J. Dornan¹⁶, M. Girone¹⁶, N. Marinelli¹⁶, J. Nowell¹⁶, S.A. Rutherford¹⁶, J.K. Sedgbeer¹⁶, J.C. Thompson¹⁶, R. White¹⁶, V.M. Ghete¹⁷, P. Girtler¹⁷, E. Kneringer¹⁷, D. Kuhn¹⁷, G. Rudolph¹⁷, E. Bouhova-Thacker¹⁸, C.K. Bowdery¹⁸, D.P. Clarke¹⁸, G. Ellis¹⁸, A.J. Finch¹⁸, F. Foster¹⁸, G. Hughes¹⁸, R.W.L. Jones¹⁸, M.R. Pearson¹⁸, N.A. Robertson¹⁸, M. Smizanska¹⁸, O. van der Aa¹⁹, C. Delaere¹⁹, G. Leibenguth¹⁹, V. Lemaitre¹⁹, U. Blumenschein²⁰, F. Hölldorfer²⁰, K. Jakobs²⁰, F. Kayser²⁰, A.-S. Müller²⁰, B. Renk²⁰, H.-G. Sander²⁰, S. Schmeling²⁰, H. Wachsmuth²⁰, C. Zeitnitz²⁰, T. Ziegler²⁰, A. Bonissent²¹, P. Coyle²¹, C. Curtil²¹, A. Ealet²¹, D. Fouchez²¹, P. Payre²¹, A. Tilquin²¹, F. Ragusa²², A. David²³, H. Dietl²³, G. Ganis²³, K. Hüttmann²³, G. Lütjens²³, W. Männer²³, H.-G. Moser²³, R. Settles²³, M. Villegas²³, G. Wolf²³, J. Boucrot²⁴, O. Callot²⁴, M. Davier²⁴, L. Duflot²⁴, J.-F. Grivaz²⁴, P. Heusse²⁴, A. Jacholkowska²⁴, L. Serin²⁴, J.-J. Veillet²⁴, P. Azzurri²⁵, G. Bagliesi²⁵, T. Boccali²⁵, L. Foà²⁵, A. Giammanco²⁵, A. Giassi²⁵, F. Ligabue²⁵, A. Messineo²⁵, F. Palla²⁵, G. Sanguinetti²⁵, A. Sciabà²⁵, G. Sguazzoni²⁵, P. Spagnolo²⁵, R. Tenchini²⁵^*, A. Venturi²⁵, P.G. Verdini²⁵, O. Awunor²⁶, G.A. Blair²⁶, G. Cowan²⁶, A. Garcia-Bellido²⁶, M.G. Green²⁶, T. Medcalf²⁶, A. Misiejuk²⁶, J.A. Strong²⁶, P. Teixeira-Dias²⁶, R.W. Clifft²⁷, T.R. Edgecock²⁷, P.R. Norton²⁷, I.R. Tomalin²⁷, J.J. Ward²⁷, B. Bloch-Devaux²⁸, D. Boumediene²⁸, P. Colas²⁸, B. Fabbro²⁸, E. Lançon²⁸, M.-C. Lemaire²⁸, E. Locci²⁸, P. Perez²⁸, J. Rander²⁸, B. Tuchming²⁸, B. Vallage²⁸, A.M. Litke²⁹, G. Taylor²⁹, C.N. Booth³⁰, S. Cartwright³⁰, F. Combley³⁰, P.N. Hodgson³⁰, M. Lehto³⁰, L.F. Thompson³⁰, A. Böhrer³¹, S. Brandt³¹, C. Grupen³¹, J. Hess³¹, A. Ngac³¹, G. Prange³¹, C. Borean³², G. Giannini³², H. He³³, J. Putz³³, J. Rothberg³³, S.R. Armstrong³⁴, K. Berkelman³⁴, K. Cranmer³⁴, D.P.S. Ferguson³⁴, Y. Gao³⁴, S. González³⁴, O.J. Hayes³⁴, H. Hu³⁴, S. Jin³⁴, J. Kile³⁴, P.A. McNamara III³⁴, J. Nielsen³⁴, Y.B. Pan³⁴, J.H. von Wimmersperg-Toeller³⁴, W. Wiedenmann³⁴, J. Wu³⁴, Sau Lan Wu³⁴, X. Wu³⁴, G. Zobernig³⁴, G. Dissertori³⁵ and The ALEPH Collaboration

¹ Physikalisches Institut, RWTH-Aachen, 52056, Aachen, Germany
² Laboratoire de Physique des Particules (LAPP), IN2P3-CNRS, 74019, Annecy-le-Vieux Cedex, France
³ Institut de Física d’Altes Energies, Universitat Autònoma de Barcelona, 08193, Bellaterra (Barcelona), Spain
⁴ Dipartimento di Fisica, INFN Sezione di Bari, 70126, Bari, Italy
⁵ Institute of High Energy Physics, Academia Sinica, Beijing, P.R. China
⁶ European Laboratory for Particle Physics (CERN), 1211, Geneva 23, Switzerland
⁷ Laboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, 63177, Aubière, France
⁸ Niels Bohr Institute, 2100, Copenhagen, Denmark
⁹ Nuclear Research Center Demokritos (NRCD), 15310, Attiki, Greece
¹⁰ Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, 91128, Palaiseau Cedex, France
¹¹ Dipartimento di Fisica, Università di Firenze, INFN Sezione di Firenze, 50125, Firenze, Italy
¹² Laboratori Nazionali dell’INFN (LNF-INFN), 00044, Frascati, Italy
¹³ Department of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
¹⁴ Utah Valley State College, Orem, UT, 84058, USA
¹⁵ Kirchhoff-Institut für Physik, Universität Heidelberg, 69120, Heidelberg, Germany
¹⁶ Department of Physics, Imperial College, London, SW7 2BZ, UK
¹⁷ Institut für Experimentalphysik, Universität Innsbruck, 6020, Innsbruck, Austria
¹⁸ Department of Physics, University of Lancaster, Lancaster, LA1 4YB, UK
¹⁹ Institut de Physique Nucléaire, Département de Physique, Université Catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
²⁰ Institut für Physik, Universität Mainz, 55099, Mainz, Germany
²¹ Centre de Physique des Particules de Marseille, Univ Méditerranée, IN2P3-CNRS, 13288, Marseille, France
²² Dipartimento di Fisica, Università di Milano e INFN Sezione di Milano, 20133, Milano, Italy
²³ Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, 80805, München, Germany
²⁴ Laboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, IN2P3-CNRS, 91898, Orsay Cedex, France
²⁵ Dipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 56010, Pisa, Italy
²⁶ Department of Physics, Royal Holloway & Bedford New College, University of London, Egham, Surrey, TW20 OEX, UK
²⁷ Particle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 OQX, UK
²⁸ CEA, DAPNIA/Service de Physique des Particules, CE-Saclay, 91191, Gif-sur-Yvette Cedex, France
²⁹ Institute for Particle Physics, University of California at Santa Cruz, Santa Cruz, CA, 95064, USA
³⁰ Department of Physics, University of Sheffield, Sheffield, S3 7RH, UK
³¹ Fachbereich Physik, Universität Siegen, 57068, Siegen, Germany
³² Dipartimento di Fisica, Università di Trieste e INFN Sezione di Trieste, 34127, Trieste, Italy
³³ Experimental Elementary Particle Physics, University of Washington, Seattle, WA, 98195, USA
³⁴ Department of Physics, University of Wisconsin, Madison, WI, 53706, USA
³⁵ Institute for Particle Physics, ETH Hönggerberg, 8093, Zürich, Switzerland

^* e-mail: Roberto.Tenchini@cern.ch

Received: 11 May 2006
Published online: 28 November 2006

Abstract

A search for Higgs bosons produced in association with a fermion pair, and decaying to WW, is performed with the data collected by the ALEPH detector at centre-of-mass energies ranging from 191 to 209 GeV. The data correspond to an integrated luminosity of 453.2 pb^-1. Thirteen exclusive selections are developed according to the different final state topologies. No statistically significant evidence for a Higgs boson decaying into a WW pair has been found. An upper limit is derived, as a function of the Higgs boson mass, on the product of the e⁺e^-→Hff̄ cross section and the H→WW branching ratio. The data on the search for H→WW are combined with previously published ALEPH results on the search for H→γγ, to significantly extend the limits on the mass of a fermiophobic Higgs boson.

© Springer-Verlag Berlin Heidelberg, 2007