A Study of B Meson Oscillations Using Hadronic Z 0 Decays Containing Leptons The OPAL

An event sample enriched in semileptonic decays of b hadrons is selected using an inclusive lepton selection from approximately 3.0 million hadronic Z0 decays collected with the OPAL detector. This sample is used to investigate B meson oscillations by reconstructing a proper decay time for the parent of each lepton, using a jet charge method to estimate the production flavour of this parent, and using the lepton charge to tag the decay flavour. We measure the mass difference between the two Bd mass eigenstates ∆md = 0.444 ± 0.029 +0.020 −0.017 ps −1 . For the Bs system, we find ∆ms > 3.1 ps −1 at the 95% confidence level. This limit varies only a little if alternative limit setting approaches are adopted. Regions at higher ∆ms values are also excluded with some methods for setting the limit. By studying the charge symmetry of the Bd mixing structure, we are able to constrain possible CP and CPT violating effects. We measure the CP violation parameter Re ǫB = −0.006 ± 0.010 ± 0.006 and the indirect CPT violating parameter Im δB = −0.020 ± 0.016 ± 0.006 . If we invoke CPT symmetry, then we obtain Re ǫB = 0.002 ± 0.007 ± 0.003 . (Submitted to Zeitschrift für Physik C) The OPAL Collaboration K.Ackerstaff, G.Alexander, J. Allison, N.Altekamp, K.J.Anderson, S.Anderson, S.Arcelli, S.Asai, D.Axen, G.Azuelos, A.H.Ball, E. Barberio, R.J. Barlow, R.Bartoldus, J.R.Batley, S. Baumann, J. Bechtluft, C.Beeston, T.Behnke, A.N.Bell, K.W.Bell, G.Bella, S. Bentvelsen, P. Berlich, S. Bethke, O.Biebel, A.Biguzzi, S.D.Bird, V.Blobel, I.J. Bloodworth, J.E.Bloomer, M.Bobinski, P. Bock, D.Bonacorsi, M.Boutemeur, B.T.Bouwens, S. Braibant, L. Brigliadori, R.M.Brown, H.J. Burckhart, C.Burgard, R.Bürgin, P.Capiluppi, R.K.Carnegie, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, D.Chrisman, P.E.L.Clarke, I. Cohen, J.E.Conboy, O.C.Cooke, M.Cuffiani, S.Dado, C.Dallapiccola, G.M.Dallavalle, S.De Jong, L.A. del Pozo, K.Desch, M.S.Dixit, E. do Couto e Silva, M.Doucet, E.Duchovni, G.Duckeck, I.P.Duerdoth, D. Eatough, J.E.G.Edwards, P.G.Estabrooks, H.G.Evans, M.Evans, F. Fabbri, M.Fanti, A.A. Faust, F. Fiedler, M.Fierro, H.M.Fischer, I. Fleck, R. Folman, D.G.Fong, M.Foucher, A. Fürtjes, D.I. Futyan, P.Gagnon, J.W.Gary, J.Gascon, S.M.Gascon-Shotkin, N.I.Geddes, C.Geich-Gimbel, T.Geralis, G.Giacomelli, P.Giacomelli, R.Giacomelli, V.Gibson, W.R.Gibson, D.M.Gingrich, D.Glenzinski, J.Goldberg, M.J.Goodrick, W.Gorn, C.Grandi, E.Gross, J.Grunhaus, M.Gruwé, C.Hajdu, G.G.Hanson, M.Hansroul, M.Hapke, C.K.Hargrove, P.A.Hart, C.Hartmann, M.Hauschild, C.M.Hawkes, R.Hawkings, R.J.Hemingway, M.Herndon, G.Herten, R.D.Heuer, M.D.Hildreth, J.C.Hill, S.J.Hillier, T.Hilse, P.R.Hobson, R.J.Homer, A.K.Honma, D.Horváth, R.Howard, D.E.Hutchcroft, P. Igo-Kemenes, D.C. Imrie, M.R. Ingram, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, G. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, D.Karlen, V.Kartvelishvili, K.Kawagoe, T.Kawamoto, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, J.Kirk, A.Klier, S.Kluth, T.Kobayashi, M.Kobel, D.S.Koetke, T.P.Kokott, M.Kolrep, S.Komamiya, T.Kress, P.Krieger, J. von Krogh, P.Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, J.G. Layter, D. Lazic, A.M.Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, A.Macchiolo, A.Macpherson, M.Mannelli, S.Marcellini, C.Markus, A.J.Martin, J.P.Martin, G.Martinez, T.Mashimo, P.Mättig, W.J.McDonald, J.McKenna, E.A.Mckigney, T.J.McMahon, R.A.McPherson, F.Meijers, S.Menke, F.S.Merritt, H.Mes, J.Meyer, A.Michelini, G.Mikenberg, D.J.Miller, A.Mincer, R.Mir, W.Mohr, A.Montanari, T.Mori, M.Morii, U.Müller, K.Nagai, I. Nakamura, H.A.Neal, B.Nellen, R.Nisius, S.W.O’Neale, F.G.Oakham, F.Odorici, H.O.Ogren, N.J.Oldershaw, M.J.Oreglia, S.Orito, J. Pálinkás, G. Pásztor, J.R.Pater, G.N.Patrick, J. Patt, M.J. Pearce, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E.Plane, P. Poffenberger, B. Poli, A. Posthaus, H. Przysiezniak, D.L.Rees, D.Rigby, S. Robertson, S.A.Robins, N.Rodning, J.M.Roney, A.Rooke, E.Ros, A.M.Rossi, M.Rosvick, P.Routenburg, Y.Rozen, K.Runge, O.Runolfsson, U.Ruppel, D.R.Rust, R.Rylko, K. Sachs, T. Saeki, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, P. Schenk, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, H.C. Schultz-Coulon, M. Schulz, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, 1 S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, P. Szymanski, R.Tafirout, S.D.Talbot, S. Tanaka, P.Taras, S. Tarem, R.Teuscher, M.Thiergen, M.A.Thomson, E. von Törne, S. Towers, I. Trigger, E.Tsur, A.S.Turcot, M.F.Turner-Watson, P.Utzat, R.Van Kooten, M.Verzocchi, P.Vikas, E.H.Vokurka, H.Voss, F.Wäckerle, A.Wagner, C.P.Ward, D.R.Ward, P.M.Watkins, A.T.Watson, N.K.Watson, P.S.Wells, N.Wermes, J.S.White, B.Wilkens, G.W.Wilson, J.A.Wilson, G.Wolf, T.R.Wyatt, S.Yamashita, G.Yekutieli, V. Zacek, D. Zer-Zion School of Physics and Space Research, University of Birmingham, Birmingham B15 2TT, UK Dipartimento di Fisica dell’ Università di Bologna and INFN, I-40126 Bologna, Italy Physikalisches Institut, Universität Bonn, D-53115 Bonn, Germany Department of Physics, University of California, Riverside CA 92521, USA Cavendish Laboratory, Cambridge CB3 0HE, UK 6 Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, Ottawa, Ontario K1S 5B6, Canada Centre for Research in Particle Physics, Carleton University, Ottawa, Ontario K1S 5B6, Canada CERN, European Organisation for Particle Physics, CH-1211 Geneva 23, Switzerland Enrico Fermi Institute and Department of Physics, University of Chicago, Chicago IL 60637, USA Fakultät für Physik, Albert Ludwigs Universität, D-79104 Freiburg, Germany Physikalisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany Indiana University, Department of Physics, Swain Hall West 117, Bloomington IN 47405, USA Queen Mary and Westfield College, University of London, London E1 4NS, UK Technische Hochschule Aachen, III Physikalisches Institut, Sommerfeldstrasse 26-28, D-52056 Aachen, Germany University College London, London WC1E 6BT, UK Department of Physics, Schuster Laboratory, The University, Manchester M13 9PL, UK Department of Physics, University of Maryland, College Park, MD 20742, USA Laboratoire de Physique Nucléaire, Université de Montréal, Montréal, Quebec H3C 3J7, Canada University of Oregon, Department of Physics, Eugene OR 97403, USA Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, UK Department of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel Department of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel International Centre for Elementary Particle Physics and Department of Physics, University of Tokyo, Tokyo 113, and Kobe University, Kobe 657, Japan Brunel University, Uxbridge, Middlesex UB8 3PH, UK Particle Physics Department, Weizmann Institute of Science, Rehovot 76100, Israel Universität Hamburg/DESY, II Institut für Experimental Physik, Notkestrasse 85, D-22607 Hamburg, Germany University of Victoria, Department of Physics, P O Box 3055, Victoria BC V8W 3P6, Canada University of British Columbia, Department of Physics, Vancouver BC V6T 1Z1, Canada University of Alberta, Department of Physics, Edmonton AB T6G 2J1, Canada 2 Duke University, Dept of Physics, Durham, NC 27708-0305, USA Research Institute for Particle and Nuclear Physics, H-1525 Budapest, P O Box 49, Hungary Institute of Nuclear Research, H-4001 Debrecen, P O Box 51, Hungary Ludwigs-Maximilians-Universität München, Sektion Physik, Am Coulombwall 1, D-85748 Garching, Germany a and at TRIUMF, Vancouver, Canada V6T 2A3 b and Royal Society University Research Fellow c and Institute of Nuclear Research, Debrecen, Hungary d and Department of Experimental Physics, Lajos Kossuth University, Debrecen, Hungary e and Depart of Physics, New York University, NY 1003, USA