Eur. Phys. J. C 22, 201-215 (2001)
DOI: 10.1007/s100520100812
Measurement of
using inclusive
b-hadron decays
The ALEPH Collaboration1, A. Heister1, S. Schael R. Barate1, 2, I. De Bonis2, D. Decamp2, C. Goy2, J.-P. Lees2, E. Merle2, M.-N. Minard2, B. Pietrzyk2, S. Bravo3, M.P. Casado3, M. Chmeissani3, J.M. Crespo3, E. Fernandez3, M. Fernandez-Bosman3, Ll. Garrido3, E. Graugés3, M. Martinez3, G. Merino3, R. Miquel3, Ll.M. Mir3, A. Pacheco3, H. Ruiz3, A. Colaleo4, D. Creanza4, 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, P. Azzurri6, G. Boix6, O. Buchmüller6, M. Cattaneo6, F. Cerutti6, B. Clerbaux6, G. Dissertori6, H. Drevermann6, R.W. Forty6, M. Frank6, T.C. Greening6, J.B. Hansen6, J. Harvey6, P. Janot6, B. Jost6, M. Kado6, P. Mato6, A. Moutoussi6, F. Ranjard6, L. Rolandi6, D. Schlatter6, O. Schneider6, W. Tejessy6, F. Teubert6, E. Tournefier6, J. Ward6, Z. Ajaltouni7, F. Badaud7, A. Falvard7, P. Gay7, P. Henrard7, J. Jousset7, B. Michel7, S. Monteil7, J-C. Montret7, D. Pallin7, P. Perret7, F. Podlyski7, J.D. Hansen8, J.R. Hansen8, P.H. Hansen8, B.S. Nilsson8, A. Wäänänen8, A. Kyriakis9, C. Markou9, E. Simopoulou9, A. Vayaki9, K. Zachariadou9, A. Blondel10, G. Bonneaud10, J.-C. Brient10, A. Rougé10, M. Rumpf10, M. Swynghedauw10, M. Verderi10, H. Videau10, V. Ciulli11, E. Focardi11, G. Parrini11, A. Antonelli12, M. Antonelli12, G. Bencivenni12, G. Bologna12, F. Bossi12, P. Campana12, G. Capon12, V. Chiarella12, P. Laurelli12, G. Mannocchi12, F. Murtas12, G.P. Murtas12, L. Passalacqua12, M. Pepe-Altarelli12, P. Spagnolo12, A.W. Halley13, J.G. Lynch13, P. Negus13, V. O'Shea13, C. Raine13, A.S. Thompson13, S. Wasserbaech14, R. Cavanaugh15, S. Dhamotharan15, C. Geweniger15, P. Hanke15, G. Hansper15, V. Hepp15, E.E. Kluge15, A. Putzer15, J. Sommer15, K. Tittel15, S. Werner15, M. Wunsch15, R. Beuselinck16, D.M. Binnie16, W. Cameron16, P.J. Dornan16, M. Girone16, N. Marinelli16, J.K. Sedgbeer16, J.C. Thompson16, V.M. Ghete17, P. Girtler17, E. Kneringer17, D. Kuhn17, G. Rudolph17, E. Bouhova-Thacker18, C.K. Bowdery18, A.J. Finch18, F. Foster18, G. Hughes18, R.W.L. Jones18, M.R. Pearson18, N.A. Robertson18, I. Giehl19, K. Jakobs19, K. Kleinknecht19, G. Quast19, B. Renk19, E. Rohne19, H.-G. Sander19, H. Wachsmuth19, C. Zeitnitz19, A. Bonissent20, J. Carr20, P. Coyle20, O. Leroy20, P. Payre20, D. Rousseau20, M. Talby20, M. Aleppo21, F. Ragusa21, A. David22, H. Dietl22, G. Ganis22, K. Hüttmann22, G. Lütjens22, C. Mannert22, W. Männer22, H.-G. Moser22, R. Settles22, H. Stenzel22, W. Wiedenmann22, G. Wolf22, J. Boucrot23, O. Callot23, M. Davier23, L. Duflot23, J.-F. Grivaz23, Ph. Heusse23, A. Jacholkowska23, J. Lefrançois23, J.-J. Veillet23, I. Videau23, C. Yuan23, G. Bagliesi24, T. Boccali24, G. Calderini24, L. Foà24, A. Giammanco24, A. Giassi24, F. Ligabue24, A. Messineo24, F. Palla24, G. Sanguinetti24, A. Sciabà24, G. Sguazzoni24, R. Tenchini24, A. Venturi24, P.G. Verdini24, G.A. Blair25, G. Cowan25, M.G. Green25, T. Medcalf25, A. Misiejuk25, J.A. Strong25, P. Teixeira-Dias25, J.H. von Wimmersperg-Toeller25, R.W. Clifft26, T.R. Edgecock26, P.R. Norton26, I.R. Tomalin26, B. Bloch-Devaux27, P. Colas27, S. Emery27, W. Kozanecki27, E. Lançon27, M.-C. Lemaire27, E. Locci27, P. Perez27, J. Rander27, J.-F. Renardy27, A. Roussarie27, J.-P. Schuller27, J. Schwindling27, A. Trabelsi27, B. Vallage27, N. Konstantinidis28, A.M. Litke28, G. Taylor28, C.N. Booth29, S. Cartwright29, F. Combley29, M. Lehto29, L.F. Thompson29, K. Affholderbach30, A. Böhrer30, S. Brandt30, C. Grupen30, A. Ngac30, G. Prange30, U. Sieler30, G. Giannini31, J. Rothberg32, S.R. Armstrong33, K. Cranmer33, P. Elmer33, D.P.S. Ferguson33, Y. Gao33, S. González33, O.J. Hayes33, H. Hu33, S. Jin33, J. Kile33, P.A. McNamara III33, J. Nielsen33, W. Orejudos33, Y.B. Pan33, Y. Saadi33, I.J. Scott33, J. Walsh33, Sau Lan Wu33, X. Wu33 and G. Zobernig33
1 Physikalisches Institut das RWTH-Aachen, 52056 Aachen, Germany
2 Laboratoire de Physique des Particules (LAPP), IN 2P 3-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, IN 2P 3-CNRS, Clermont-Ferrand, 63177 Aubière, France
8 Niels Bohr Institute, 2100 Copenhagen, Denmark
9 Nuclear Research Center Demokritos (NRCD), 15310 Attiki, Greece
10 Laboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN 2P 3-CNRS, 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 Department of Physics, Haverford College, Haverford, PA 19041-1392, 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 für Physik, Universität Mainz, 55099 Mainz, Germany
20 Centre de Physique des Particules, Université de la Méditerranée, IN 2P 3-CNRS, 13288 Marseille, France
21 Dipartimento di Fisica, Università di Milano e INFN Sezione di Milano, 20133 Milano, Italy
22 Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, 80805 München, Germany
23 Laboratoire de l'Accélérateur Linéaire, Université de Paris-Sud, IN 2P 3-CNRS, 91898 Orsay Cedex, France
24 Dipartimento di Fisica dell'Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 56010 Pisa, Italy
25 Department of Physics, Royal Holloway & Bedford New College, University of London, Egham, Surrey TW20 OEX, UK
26 Particle Physics Dept., Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 OQX, UK
27 CEA, DAPNIA/Service de Physique des Particules, CE-Saclay, 91191 Gif-sur-Yvette Cedex, France
28 Institute for Particle Physics, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
29 Department of Physics, University of Sheffield, Sheffield S3 7RH, UK
30 Fachbereich Physik, Universität Siegen, 57068 Siegen, Germany
31 Dipartimento di Fisica, Università di Trieste e INFN Sezione di Trieste, 34127 Trieste, Italy
32 Experimental Elementary Particle Physics, University of Washington, Seattle, WA 98195, USA
33 Department of Physics, University of Wisconsin, Madison, WI 53706, USA
(Received: 4 July 2001 / Published online: 12 November 2001 - © Springer-Verlag / Società Italiana di Fisica 2001 )
Abstract
Based on a sample of four million events collected by ALEPH from
1991 to 1995, a
measurement of the forward-backward asymmetry in
decays using inclusive final states
is presented.
High-performance tagging of
events
in a wide angular range is achieved using neural network techniques.
An optimal hemisphere charge estimator is built by merging
primary and secondary vertex information, leading kaon
identification and jet charge in a neural network. The
average charge asymmetry, the flavour
tagging efficiencies and mean
b-hemisphere charges are measured
from data and used to extract the pole
b asymmetry
in the Standard Model
corresponding to a value of the effective weak
mixing angle of
© Società Italiana di Fisica, Springer-Verlag 2001