Using data collected with the OPAL detector at LEP, we have searched for the processes ee → Z → pe−,pμ− and the charge conjugate final-states. These would violate the conservation of the baryon-number B, lepton-number L and the fermion-number n = (B+L). No evidence for such decays has been found, and the 95 % confidence level upper limits on the partial widths Γ(Z → pe) and Γ(Z → pμ) are found to be 4.6 and 4.4 keV respectively. (Submitted to Physics Letters B) The OPAL Collaboration G.Abbiendi, K.Ackerstaff, G.Alexander, J. Allison, N.Altekamp, K.J.Anderson, S.Anderson, S.Arcelli, S.Asai, S.F.Ashby, D.Axen, G.Azuelos, A.H.Ball, E. Barberio, R.J. Barlow, R.Bartoldus, J.R.Batley, S. Baumann, J. Bechtluft, T.Behnke, K.W.Bell, G.Bella, A.Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O.Biebel, A.Biguzzi, S.D.Bird, V.Blobel, I.J. Bloodworth, P. Bock, J. Böhme, D.Bonacorsi, M.Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M.Brown, H.J. Burckhart, P.Capiluppi, R.K.Carnegie, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, D.Chrisman, C.Ciocca, P.E.L.Clarke, E.Clay, I. Cohen, J.E.Conboy, O.C.Cooke, C.Couyoumtzelis, R.L.Coxe, M.Cuffiani, S.Dado, G.M.Dallavalle, R.Davis, S.De Jong, A. de Roeck, P.Dervan, K.Desch, B.Dienes, M.S.Dixit, J.Dubbert, E.Duchovni, G.Duckeck, I.P.Duerdoth, D. Eatough, P.G.Estabrooks, E. Etzion, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P.Gagnon, J.W.Gary, J.Gascon, S.M.Gascon-Shotkin, G.Gaycken, C.Geich-Gimbel, G.Giacomelli, P.Giacomelli, V.Gibson, W.R.Gibson, D.M.Gingrich, D.Glenzinski, J.Goldberg, W.Gorn, C.Grandi, K.Graham, E.Gross, J.Grunhaus, M.Gruwé, G.G.Hanson, M.Hansroul, M.Hapke, K.Harder, A.Harel, C.K.Hargrove, 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, P.R.Hobson, M.Hoch, A.Hocker, K.Hoffman, R.J.Homer, A.K.Honma, D.Horváth, K.R.Hossain, R.Howard, P.Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D.Karlen, V.Kartvelishvili, K.Kawagoe, T.Kawamoto, P.I.Kayal, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, D.H.Kim, A.Klier, S.Kluth, T.Kobayashi, M.Kobel, D.S.Koetke, T.P.Kokott, M.Kolrep, S.Komamiya, R.V.Kowalewski, T.Kress, P.Krieger, J. von Krogh, T.Kuhl, P.Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W.Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A.Macchiolo, A.Macpherson, W.Mader, M.Mannelli, S.Marcellini, C.Markopoulos, 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, S.Mihara, G.Mikenberg, D.J.Miller, R.Mir, W.Mohr, A.Montanari, T.Mori, K.Nagai, I. Nakamura, H.A.Neal, B.Nellen, R.Nisius, S.W.O’Neale, F.G.Oakham, F.Odorici, H.O.Ogren, M.J.Oreglia, S.Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N.Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, J. Polok, M.Przybycień, C.Rembser, H.Rick, S. Robertson, S.A.Robins, N.Rodning, J.M.Roney, K.Roscoe, A.M.Rossi, Y.Rozen, K.Runge, O.Runolfsson, D.R.Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick , W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold,

From data collected around the Z0 resonance by the OPAL detector at LEP, a sample of Bs decays was obtained using D − s l + combinations, where the D−s was fully reconstructed in the φπ−, K∗0K− and KsK − decay channels or partially reconstructed in the φl−ν̄(X) decay channel. These events were used to study Bs oscillation. The flavor (b or b̄) at decay was determined from the lepton charge while the flavor at production was determined from a combination of techniques. The expected sensitivity of the experiment is 4.1 ps−1. The experiment was not able to resolve the oscillatory behavior, and we deduced that the Bs oscillation frequency ∆ms > 1.0 ps −1 at the 95% confidence level. (Submitted to Euro. Phys. Jour.) The OPAL Collaboration G.Abbiendi, C.Ainsley, P.F. Åkesson, G.Alexander, J. Allison, G.Anagnostou, K.J.Anderson, S.Arcelli, S.Asai, D.Axen, G.Azuelos, I. Bailey, A.H.Ball, E. Barberio, R.J. Barlow, T.Behnke, K.W.Bell, G.Bella, A.Bellerive, G.Benelli, S. Bentvelsen, S. Bethke, O.Biebel, I.J. Bloodworth, O.Boeriu, P. Bock, J. Böhme , D.Bonacorsi, M.Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M.Brown, H.J. Burckhart, J. Cammin, P.Capiluppi, R.K.Carnegie, B.Caron, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, P.E.L.Clarke, E.Clay, I. Cohen, O.C.Cooke, J. Couchman, R.L.Coxe, A.Csilling, M.Cuffiani, S.Dado, G.M.Dallavalle, S.Dallison, A.De Roeck, E.A.De Wolf, P.Dervan, K.Desch, B.Dienes , M.S.Dixit, M.Donkers, J.Dubbert, E.Duchovni, G.Duckeck, I.P.Duerdoth, P.G.Estabrooks, E. Etzion, F. Fabbri, M. Fanti, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P.Gagnon, J.W.Gary, G.Gaycken, C.Geich-Gimbel, G.Giacomelli, P.Giacomelli, D.Glenzinski, J.Goldberg, C.Grandi, K.Graham, E.Gross, J.Grunhaus, M.Gruwé, P.O.Günther, C.Hajdu, G.G.Hanson, K.Harder, A.Harel, M.Harin-Dirac, M.Hauschild, C.M.Hawkes, R.Hawkings, R.J.Hemingway, C.Hensel, G.Herten, R.D.Heuer, J.C.Hill, A.Hocker, K.Hoffman, R.J.Homer, A.K.Honma, D.Horváth, K.R.Hossain, R.Howard, P.Hüntemeyer, P. Igo-Kemenes, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N.Kanaya, J.Kanzaki, G.Karapetian, D.Karlen, V.Kartvelishvili, K.Kawagoe, T.Kawamoto, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, D.H.Kim, K.Klein, A.Klier, S.Kluth, T.Kobayashi, M.Kobel, T.P.Kokott, S.Komamiya, R.V.Kowalewski, T.Kress, P.Krieger, J. von Krogh, D.Krop, T.Kuhl, M.Kupper, P.Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, C. Littlewood, A.W.Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A.Macchiolo, A.Macpherson, W.Mader, S.Marcellini, T.E.Marchant, A.J.Martin, J.P.Martin, G.Martinez, T.Mashimo, P.Mättig, W.J.McDonald, J.McKenna, T.J.McMahon, R.A.McPherson, F.Meijers, P.Mendez-Lorenzo, W.Menges, F.S.Merritt, H.Mes, A.Michelini, S.Mihara, G.Mikenberg, D.J.Miller, W.Mohr, A.Montanari, T.Mori, K.Nagai, I. Nakamura, H.A.Neal, R.Nisius, S.W.O’Neale, F.G.Oakham, F.Odorici, A.Oh, A.Okpara, M.J.Oreglia, S.Orito, G. Pásztor, J.R. Pater, G.N.Patrick, P. Pfeifenschneider , J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, M.Przybycień, A.Quadt, K.Rabbertz, C.Rembser, P.Renkel, H.Rick, N.Rodning, J.M.Roney, S. Rosati, K.Roscoe, A.M.Rossi, Y.Rozen, K.Runge, O.Runolfsson, D.R.Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher , C. Schwick, W.G. Scott, R. Seuster , T.G. Shears , B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, L. Stumpf, B. Surrow, S.D.Talbot, S. Tarem, R.J. Taylor, R.Teuscher, J. Thomas, M.A.Thomson, M.Tönnesmann, E.Torrence, S. Towers, D.Toya, T.Trefzger, I. Trigger, Z. Trócsányi , E.Tsur, M.F.Turner-Watson, I. Ueda, B.Vachon, P.Vannerem,

Results are presented on the production of excited charm and excited charm-strange mesons in hadronic Z0 decays. The results are obtained from approximately 4.3 million hadronic Z0 decays, collected on or near the Z0 resonance using the OPAL detector at LEP. The D~(2420) and D2°(2460) mesons are reconstructed in the n•+"final state and their separate production rates in charm fragmentation and in weak decays of bhadrons are determined. From these measurements, the charm hadronization fractions and the inclusive branching ratios ofb-hadrons to these neutral P-wave charm mesons are determined to be f(cD~) f(c-D2°) f(bD~) f(bD2°) 0.021 ± 0.007( stat) ± 0.003( syst ), 0.052 ± 0.022(stat) ± 0.013( syst ), 0.050 ± 0.014(stat) ± 0.006(syst), 0.04 7 ± 0.024(stat) ± 0.013( syst ). We also present the first observation at LEP of the D;i (2536) meson which is reconstructed in both the D*+K~ and D*°K+ final states. After correcting for the expected contribution from bb events, these results are used to derive the charm hadronization fraction f( c ~ D;i): f(c ~ D;i) = 0.016 ± 0.004(stat) ± 0.003(syst). (To be submitted to Zeitschrift fiir Physik C) The OPAL Collaboration K. Ackersta:ffS, G. Alexander23 , J. Allison16 , N. Altekamp5 , K.J. Anderson9 , S. Anderson12 , S.Arcell?, S.Asai , D.Axen 29 , G.Azuelos18·a, A.H.BalF 7 , E.Barberio , R.J.Barlow , R.Bartoldus3 , J.R.Batley5 , S.Baumann3 , J.Bechtluft1\ C.Beeston , T.Behnke , A.N.BelF, K.W. Bell20 , G. Bella , S. Bentvelsen , P. Berlich , S. Bethke1\ 0. BiebeF\ A. Biguzzi5 , S.D. Bird16 , V. BlobeJ2 , I.J. Bloodworth1 , J .E. Bloomer , M. Bobinski , P. BocPl, D. Bonacors?, M. Boutemeur3\ B.T. Bouwens , S. Braibant , L. Brigliador?, R.M. Brown , H.J. Burckhart8 , C. Burgard8 , R. Biirgin10 , P. Capilupp?, R.K. Carnegie6 , A.A. Carter13, J.R. Carter5 , C.Y. Chang17 , D.G. Charlton1•b, D. Chrisman\ P.E.L. Clarke15 , I. Cohen23 , J.E.Conboy15 , O.C.Cooke16 , M.Cuffian?, S.Dado , C.Dallapiccola , G.M.Dallavalle , S.De Jong , L.A. del Pozo\ K.Desch , M.S.Dixit 7 , E. do Couto e Silva , M.Doucet , E. Duchovn?6 , G. Duckeck\ I.P. Duerdoth , D. Eatough , J.E.G. Edwards , P.G. Estabrooks6 , H.G. Evans9 , M. Evans13 , F. Fabbr?, M. Fanti2 , A.A. Faust30 , F. Fiedler27 , M. Fierro , H.M. Fischer\ I. Fleck , R. Folman , D.G. Fong , M. Foucher , A. Fiirtjes , D.I. Futyan16, P. Gagnon', J.W. Gary\ J. Gascon , S.M. Gascon-Shotkin17 , N.I. Geddes 20 , C. Geich-Gimbel , T. Geralis20 , G. Giacomelli , P. Giacomelli , R. Giacomell?, V. Gibson , W.R.Gibson13 , D.M.Gingrich30·", D.Glenzinski , J.Goldberg , M.J.Goodrick , W.Gorn\ C.Grandi2 , E.Gross 26 , J.Grunhaus 23 , M.Gruwe , C.Hajdu32 , G.G.Hanson , M.Hansroul8 , M. Hapke13 , C.K. Hargrove , P.A. Hart , C. Hartmann , M. Hauschild , C.M. Hawkes", R.Hawkings27 , R.J.Hemingway , M.Herndon, G.Herten, R.D.Heuer , M.D.Hildreth , J .C. HillS, S.J. Hillier1 , T. Hilse10 , P.R. Hobson25 , R.J. Homer\ A.K. Honma28·", D. Horvath ·c, R. Howard29 , D.E. Hutchcroft5 , P. Igo-Kemenes , D.C. Imrie , M.R. Ingram , K. Ishii\ A.Jawahery17 , P.W.Jeffreys20 , H.Jeremie, M.Jimackl, A.Joly , C.R.Jones , G.Jones , M.Jones6 , U.Jost11, P.Jovanovic , T.R.Junk", D.Karlen6 , V.Kartvelishvili , K.Kawagoe\ T. Kawamoto2\ R.K. Keeler28 , R.G. Kellogg , B.W. Kennedy, J. Kirk , A. Klier , S. Kluth8 , T. Kobayash?\ M. KobeF0 , D.S. Koetke , T.P. Kokotts, M. Kolrep , S. Komamiya2\ T. Kress 11 , P. Krieger6 , J. von Krogh1 \ P. Kyberds, G.D. Lafferty , R. Lahmann17 , W.P. Lai19 , D. Lanske1\ J. Lauber15 , S.R. Lautenschlagers\ J.G. Layter\ D.Lazic22 , A.M.Lee31, E.Lefebvre18 , D.Lellouch , J.Letts12 , L.Levinson , S.L.Lloyds, F .K. Loebinger16 , G.D. Long28 , M.J. Losty7 , J. Ludwig10 , A. Macchiolo , A. Macpherson so, M. Mannelli8 , S. Marcellini2 , C. Markuss, A.J. Martin1s, J.P. Martin18 , G. Martinez , T. Mashimo2\ P. Miittigs, W.J. McDonald , J. McKenna , E.A. Mckigney, T.J. McMahon\ R.A. McPherson8 , F. Meijers8 , S. Menkes, F.S. Merritt9 , H. Mes7 , J. Meyer27, A. Michelin?, G. Mikenberg26 , D.J. Miller15 , A. Mincer22·e, R. Mir , W. Mohr10 , A. Montanari , T. Mor?\ M.Morii2\ U.Miillers, K.Nagai26 , 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.Orito2\ J.Palinkas33·d, G.Pasztor32 , J.R.Pater16 , G.N.Patrick , J.Patt10 , M.J.Pearcel, S. Petzold27 , P. Pfeifenschneider14 , J .E. Pilcher9 , 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. Rozen22 , K. Runge10 , 0. Runolfsson8 , U. Ruppel\ D.R. Rust , R. Rylko , K. Sachs , T. Saeki2\ E.K.G. Sarkisyan2S, C. Sbarra29 , A.D. Schailes\ 0. Schaile\ F. Scharf\ P. Scharff-Hansen8 , P. Schenk3\ J. Schieck11 , P. Schleper11 , B. Schmitt , S. Schmitt ,

M easurem entsofthe lepton polarization and forward-backward polarization asym m etry near the Z resonance using the O PAL detector are described. The m easurem ents are based on analyses of ! e e , ! , ! , ! and ! a1 decays from a sam ple of 144;810 e e ! + candidates corresponding to an integrated lum inosity of 151 pb . Assum ing thatthe lepton decays according to V A theory,we m easure the average polarization near p s = M Z to be hP i = ( 14:10 0:73 0:55)% and the polarization forward-backward asym m etry to be A FB pol = ( 10:55 0:76 0:25)% ,where the rst error isstatisticaland the second system atic. Taking into account the sm alle ects ofthe photon propagator,photon-Z interference and photonic radiative corrections,these results can be expressed in term softhelepton neutralcurrentasym m etry param eters:

The production of K(S)(0) and Lambda hadrons is studied in pp collision data at root s = 0.9 and 7 TeV collected with the ATLAS detector at the LHC using a minimum-bias trigger. The observed distributions of transverse momentum, rapidity, and multiplicity are corrected to hadron level in a model-independent way within well-defined phase-space regions. The distribution of the production ratio of (Lambda) over bar to Lambda baryons is also measured. The results are compared with various Monte Carlo simulation models. Although most of these models agree with data to within 15% in the K(S)(0) distributions, substantial disagreements are found in the Lambda distributions of transverse momentum.

Events with four distinct jets from e + e − collisions, collected by the OPAL detector at centre-of-mass energies between 130 and 184 GeV, are analysed for a peak in the sum of dijet masses. This search is motivated by the ALEPH Collaboration's observation of a clear excess of events with dijet mass sums close to 105 GeV in data taken at centre-of-mass energies of 130 and 136 GeV in 1995. We have observed no significant excess of four-jet events compared to the Standard Model expectation for any dijet mass sum at any energy. Our observation is inconsistent with the excess observed by ALEPH in 1995. Upper limits are determined on the production cross-section as a function of the dijet mass sum.

The τ− → μ−ν̄μντ branching ratio has been measured using data collected from 1990 to 1995 by the OPAL detector at the LEP collider. The resulting value of B(τ− → μ−ν̄μντ ) = 0.1734 ± 0.0009(stat) ± 0.0006(syst) has been used in conjunction with other OPAL measurements to test lepton universality, yielding the coupling constant ratios gμ/ge = 1.0005± 0.0044 and gτ/ge = 1.0031± 0.0048, in good agreement with the Standard Model prediction of unity. A value for the Michel parameter η = 0.004 ± 0.037 has also been determined and used to find a limit for the mass of the charged Higgs boson, mH± > 1.28 tan β, in the Minimal Supersymmetric Standard Model. (To be submitted to Physics Letters B) The OPAL Collaboration G. Abbiendi2, C.Ainsley5, P.F. Åkesson3, G. Alexander22, J. Allison16, P.Amaral9, G. Anagnostou1, K.J.Anderson9, S.Arcelli2, S.Asai23, D. Axen27, G. Azuelos18,a, I. Bailey26, E.Barberio8,p, R.J. Barlow16, R.J. Batley5, P.Bechtle25 , T.Behnke25, K.W. Bell20, P.J. Bell1, G.Bella22, A. Bellerive6, G. Benelli4, S. Bethke32, O.Biebel31, I.J. Bloodworth1, O.Boeriu10, P.Bock11, D. Bonacorsi2, M. Boutemeur31, S. Braibant8, L. Brigliadori2, R.M. Brown20, K.Buesser25, H.J. Burckhart8, S. Campana4, R.K.Carnegie6, B. Caron28, A.A. Carter13, J.R.Carter5, C.Y. Chang17, D.G. Charlton1,b, A.Csilling8,g, M. Cuffiani2, S.Dado21, S.Dallison16, A.De Roeck8, E.A. De Wolf8,s, K.Desch25, B. Dienes30, M.Donkers6, J.Dubbert31, E.Duchovni24, G.Duckeck31 , I.P. Duerdoth16, E. Elfgren18, E. Etzion22, F. Fabbri2, L. Feld10, P. Ferrari8, F. Fiedler31, I. Fleck10, M. Ford5, A. Frey8, A. Fürtjes8, P.Gagnon12, J.W. Gary4, G. Gaycken25, C.Geich-Gimbel3, G. Giacomelli2, P.Giacomelli2 , M. Giunta4, J.Goldberg21, E. Gross24, J.Grunhaus22, M.Gruwé8, P.O. Günther3, A.Gupta9, C.Hajdu29, M. Hamann25, G.G. Hanson4, K.Harder25, A. Harel21, M. Harin-Dirac4, M. Hauschild8, J.Hauschildt25, C.M.Hawkes1, R.Hawkings8, R.J. Hemingway6, C.Hensel25, G. Herten10, R.D. Heuer25, J.C.Hill5, K.Hoffman9, R.J. Homer1, D. Horváth29,c, R. Howard27, P. Igo-Kemenes11, K. Ishii23, H. Jeremie18, P. Jovanovic1, T.R. Junk6, N. Kanaya26, J.Kanzaki23, G.Karapetian18, D. Karlen6, V.Kartvelishvili16, K.Kawagoe23, T.Kawamoto23, R.K.Keeler26, R.G. Kellogg17, B.W. Kennedy20, D.H. Kim19, K.Klein11,t, A. Klier24, S.Kluth32, T.Kobayashi23, M. Kobel3, S.Komamiya23, L.Kormos26, T.Krämer25, T.Kress4, P.Krieger6,l, J. von Krogh11, D. Krop12, K.Kruger8, T.Kuhl25, M. Kupper24, G.D. Lafferty16, H. Landsman21, D. Lanske14, J.G. Layter4, A. Leins31, D. Lellouch24, J. Letts, L. Levinson24, J. Lillich10, S.L. Lloyd13, F.K. Loebinger16, J. Lu27, J. Ludwig10, A.Macpherson28,i, W. Mader3, S.Marcellini2, T.E.Marchant16, A.J.Martin13, J.P. Martin18, G.Masetti2, T.Mashimo23, P. Mättig, W.J. McDonald28, J.McKenna27, T.J. McMahon1, R.A.McPherson26, F. Meijers8, P. Mendez-Lorenzo31, W. Menges25, F.S. Merritt9, H.Mes6,a, A. Michelini2, S.Mihara23, G. Mikenberg24, D.J. Miller15, S.Moed21, W.Mohr10, T.Mori23, A.Mutter10, K.Nagai13, I. Nakamura23, H.A. Neal33, R. Nisius32, S.W.O’Neale1, A. Oh8, A.Okpara11, M.J. Oreglia9, S.Orito23, C. Pahl32, G.Pásztor4,g, J.R.Pater16, G.N. Patrick20, J.E. Pilcher9, J. Pinfold28, D.E. Plane8, B. Poli2, J. Polok8, O.Pooth14, M. Przybycień8,n, A. Quadt3, K. Rabbertz8,r, C.Rembser8, P. Renkel24, H.Rick4, J.M. Roney26, S.Rosati3, Y. Rozen21, K. Runge10, K. Sachs6, T. Saeki23, O. Sahr31, E.K.G. Sarkisyan8,j , A.D. Schaile31, O. Schaile31, P. Scharff-Hansen8, J. Schieck32, T. Schörner-Sadenius8, M. Schröder8, M. Schumacher3, C. Schwick8, W.G. Scott20, R. Seuster14,f , T.G. Shears8,h, B.C. Shen4, P. Sherwood15, G. Siroli2, A. Skuja17, A.M. Smith8, R. Sobie26, S. Söldner-Rembold10,d, F. Spano9, A. Stahl3, K. Stephens16, D. Strom19, R. Ströhmer31, S. Tarem21, M.Tasevsky8, R.J.Taylor15, R.Teuscher9, M.A. Thomson5, E.Torrence19, D. Toya23, P. Tran4, T.Trefzger31, A. Tricoli2, I. Trigger8, Z.Trócsányi30,e, E.Tsur22, M.F. Turner-Watson1, I. Ueda23, B. Ujvári30,e, B. Vachon26, C.F. Vollmer31, P.Vannerem10, M. Verzocchi17, H. Voss8,q, J.Vossebeld8,h, D.Waller6, C.P. Ward5, D.R. Ward5, P.M. Watkins1, A.T.Watson1, N.K.Watson1, P.S.Wells8, T.Wengler8, N. Wermes3, D. Wetterling11 G.W. Wilson16,k, J.A. Wilson1, G. Wolf24, T.R.Wyatt16, S.Yamashita23, D. Zer-Zion4, L. Zivkovic24 1School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK 2Dipartimento di Fisica dell’ Università di Bologna and INFN, I-40126 Bologna, Italy 3Physikalisches Institut, Universität Bonn, D-53115 Bonn, Germany 4Department of Physics, University of California, Riverside CA 92521, USA 5Cavendish Laboratory, Cambridge CB3 0HE, UK 6Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, Ottawa, Ontario K1S

We have analysed the data collected by OPAL at centre-of-mass energies between 189 and 209 GeV searching for Higgs boson candidates from the process ee → hZ followed by the decay of h → AA where A is the CP-odd Higgs boson. The search is done in the region where the A mass, mA, is below the production threshold for bb̄, and the CP-even Higgs boson mass mh is within the range 45–86 GeV/c . In this kinematic range, the decay of h → AA may be dominant and previous Higgs boson searches have very small sensitivities. This search can be interpreted within any model that predicts the existence of at least one scalar and one pseudoscalar Higgs boson. No excess of events is observed above the expected Standard Model backgrounds. Model-independent limits on the cross-section for the process ee → hZ are derived assuming 100% decays of the h into AA and 100% decays of the AA into each of the following final states: cc̄cc̄, gggg, ττττ, cc̄gg, ggττand cc̄ττ. The results are also interpreted in the CP-conserving no-mixing MSSM scenario, where the region 45 ≤ mh ≤ 85 GeV/c and 2 ≤ mA ≤ 9.5 GeV/c is excluded. To be submitted to European Physics Journal C G.Abbiendi, C.Ainsley, P.F. Åkesson, G.Alexander, J. Allison, P.Amaral, G.Anagnostou, K.J.Anderson, S.Arcelli, S.Asai, D.Axen, G.Azuelos, I. Bailey, E. Barberio, R.J. Barlow, R.J. Batley, P. Bechtle, T.Behnke, K.W.Bell, P.J. Bell, G.Bella, A.Bellerive, G.Benelli, S. Bethke, O.Biebel, I.J. Bloodworth, O.Boeriu, P. Bock, D.Bonacorsi, M.Boutemeur, S. Braibant, L. Brigliadori, R.M.Brown, K.Buesser, H.J. Burckhart, S. Campana, R.K.Carnegie, B.Caron, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, A.Csilling, M.Cuffiani, S.Dado, G.M.Dallavalle, S.Dallison, A.De Roeck, E.A.De Wolf, K.Desch, B.Dienes, M.Donkers, J.Dubbert, E.Duchovni, G.Duckeck, I.P.Duerdoth, E. Elfgren, E. Etzion, F. Fabbri, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M.Ford, A. Frey, A. Fürtjes, P.Gagnon, J.W.Gary, G.Gaycken, C.Geich-Gimbel, G.Giacomelli, P.Giacomelli, M.Giunta, J.Goldberg, E.Gross, J.Grunhaus, M.Gruwé, P.O.Günther, A.Gupta, C.Hajdu, M.Hamann, G.G.Hanson, K.Harder, A.Harel, M.Harin-Dirac, M.Hauschild, J. Hauschildt, C.M.Hawkes, R.Hawkings, R.J.Hemingway, C.Hensel, G.Herten, R.D.Heuer, J.C.Hill, K.Hoffman, R.J.Homer, D.Horváth, R.Howard, P.Hüntemeyer, P. Igo-Kemenes, K. Ishii, H. Jeremie, P. Jovanovic, T.R. Junk, N.Kanaya, J.Kanzaki, G.Karapetian, D.Karlen, V.Kartvelishvili, K.Kawagoe, T.Kawamoto, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, D.H.Kim, K.Klein, A.Klier, S.Kluth, T.Kobayashi, M.Kobel, S.Komamiya, L.Kormos, R.V.Kowalewski, T.Krämer, T.Kress, P.Krieger, J. von Krogh, D.Krop, K.Kruger, M.Kupper, G.D. Lafferty, H. Landsman, D. Lanske, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, J. Lillich, S.L. Lloyd, F.K. Loebinger, J. Lu, J. Ludwig, A.Macpherson, W.Mader, S.Marcellini, T.E.Marchant, A.J.Martin, J.P.Martin, G.Masetti, T.Mashimo, P.Mättig, W.J.McDonald, J.McKenna, T.J.McMahon, R.A.McPherson, F.Meijers, P.Mendez-Lorenzo, W.Menges, F.S.Merritt, H.Mes, A.Michelini, S.Mihara, G.Mikenberg, D.J.Miller, S.Moed, W.Mohr, T.Mori, A.Mutter, K.Nagai, I. Nakamura, H.A.Neal, R.Nisius, S.W.O’Neale, A.Oh, A.Okpara, M.J.Oreglia, S.Orito, C. Pahl, G. Pásztor, J.R.Pater, G.N.Patrick, J.E. Pilcher, J. Pinfold, D.E.Plane, B. Poli, J. Polok, O. Pooth, M.Przybycień, A.Quadt, K.Rabbertz, C.Rembser, P.Renkel, H.Rick, J.M.Roney, S. Rosati, Y.Rozen, K.Runge, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan , A.D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, T. Schörner-Sadenius, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster , T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G. Siroli, A. Skuja, A.M. Smith, R. Sobie, S. Söldner-Rembold, S. Spagnolo, F. Spano, A. Stahl, K. Stephens, D. Strom, R. Ströhmer, S. Tarem, M.Tasevsky, R.J.Taylor, R.Teuscher, M.A.Thomson, E.Torrence, D.Toya, P.Tran, T.Trefzger, A.Tricoli, I. Trigger, Z. Trócsányi, E.Tsur, M.F.Turner-Watson, I. Ueda, B.Ujvári, B.Vachon, C.F.Vollmer, P.Vannerem, M.Verzocchi, H.Voss, J. Vossebeld, D.Waller, C.P.Ward, D.R.Ward, P.M.Watkins, A.T.Watson, N.K.Watson, P.S.Wells, T.Wengler, N.Wermes, D.Wetterling G.W.Wilson, J.A.Wilson, G.Wolf, T.R.Wyatt, S.Yamashita, D. Zer-Zion, L. Zivkovic School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK Dipartimento di Fisica dell’ Università di Bologna and INFN, I-40126 Bologna, Italy

A search for charginos and neutralinos, predicted by supersymmetric theories, is performed using a data sample of 182.1 pb−1 taken at a centre-of-mass energy of 189 GeV with the OPAL detector at LEP. No evidence for chargino or neutralino production is found. Upper limits on chargino and neutralino pair production (χ̃1 χ̃ − 1 , χ̃ 0 1χ̃ 0 2) cross-sections are obtained as a function of the chargino mass (mχ̃± 1 ), the lightest neutralino mass (mχ̃0 1 ) and the second lightest neutralino mass (mχ̃0 2 ). Within the Constrained Minimal Supersymmetric Standard Model framework, and for mχ̃± 1 −mχ̃0 1 ≥ 5 GeV, the 95% confidence level lower limits on mχ̃± 1 are 93.6 GeV for tan β = 1.5 and 94.1 GeV for tan β = 35. These limits are obtained assuming a universal scalar mass m0 ≥ 500 GeV. The corresponding limits for all m0 are 78.0 and 71.7 GeV. The 95% confidence level lower limits on the lightest neutralino mass, valid for any value of tan β are 32.8 GeV for m0 ≥ 500 GeV and 31.6 GeV for all m0. (Submitted to Phys. Lett. B) The OPAL Collaboration G. Abbiendi, K. Ackerstaff, G. Alexander, J. Allison, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, I.J. Bloodworth, P. Bock, J. Böhme, O. Boeriu, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, R. Davis, S. De Jong, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, P. Ferrari, F. Fiedler, M. Fierro, I. Fleck, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, M. Harin-Dirac, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, A. Klier, T. Kobayashi, M. Kobel, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, I. Lawson, J.G. Layter, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, T.E. Marchant, 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, P. Mendez-Lorenzo, F.S. Merritt, H. Mes, I. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal , R. Nisius, S.W. O’Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider , J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, J. Polok, M. Przybycień, A. Quadt, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence,

The forward-backward asymmetry of e + e ? ! Z 0 ! bb has been measured using approximately 2.15 million hadronic Z 0 decays collected at the LEP e + e ? collider with the OPAL detector. A lifetime tag technique was used to select an enriched bb event sample. The measurement of the bb asymmetry was then performed using a jet charge algorithm to determine the direction of the primary quark. were measured where, in each case, the rst error is statistical, the second is systematic and the third term gives the variation due to a change (? bb =? had) in the value of ? bb =? had = 0:216 assumed. The dependence on the assumed charm asymmetry at the same energy is (A b FB) +0:077(A c FB). Assuming the Standard Model form for the couplings, these measurements correspond to an eeective weak mixing angle of: sin 2 ee;e +16 ?19 GeV/c 2 , where the rst error is statistical and the second is systematic. The Higgs mass assumed is 300 GeV/c 2. A variation in the assumed mass of the Higgs boson between 60 and 1000 GeV/c 2 corresponds to an uncertainty in sin 2 ee;e W of 0:00006 and on M top of +20 ?26 GeV/c 2 .

We report a measurement of the branching ratio B(D + ! 0 ` + `)/ B(D + ! K 0 ` + `) from the Fermilab charm hadroproduction experiment E791. Based on signals of 49 17 events in the D + ! 0 e + e mode and 54 18 events in the D + ! 0 + mode, we measure Combining the results from both the electronic and muonic modes, we obtain 2 Semileptonic charm decays are useful in probing the dynamics of hadronic currents since the Cabibbo-Kobayashi-Maskawa matrix elements for the charm sector are well-known from unitarity constraints. Form factors for Cabibbo-suppressed (CS) c ! d semileptonic decays can be related via Heavy Quark EEective Theory (HQET) to those for b ! u semileptonic decays at the same four-velocity transfer 1]. Since knowledge of the form factors in b ! u transitions is vital for extracting V ub from b ! u semileptonic decays in a model-independent way, study of c ! d semileptonic decays can improve our knowledge of V ub. Although considerable progress has been made in studying CS semileptonic charm decays to pseudoscalar mesons 2], the only previous result on CS semileptonic charm decay to a vector meson is based on four D + ! 0 + events 3]. In this Letter, we report a new measurement from the Fermilab hadroproduction experiment E791 of B(D + ! 0 ` + `)=B(D + ! K 0 ` + `) based on more than 100 D + ! 0 ` + ` decays in the combined electronic and muonic modes. The E791 experiment 4] recorded 2 10 10 events from 500 GeV/c ? interactions in ve thin targets (one platinum, four diamond) separated by gaps of 1.34 to 1.39 cm. Precision tracking and vertexing information was provided by 23 silicon microstrip detectors (6 upstream and 17 downstream of the targets) and 35 drift chamber planes. Momentum was measured with two dipole magnets. Two segmented threshold Cerenkov counters provided =K separation in the 6 ? 60 GeV/c momentum range 5]. (charge-conjugate states are implied throughout this Letter) are selected by requiring a three-prong decay vertex of charge 1 with one of the decay particles being identiied as a lepton. A segmented lead and liquid-scintillator calorimeter 6] is used to identify the electrons, based on energy deposition and transverse shower shape. The probability that a (K) is misidentiied as …

We have studied hadronic events from ee annihilation data at centre-of-mass energies from 91 to 209 GeV. We present distributions of event shape observables and their moments at each energy and compare with QCD Monte Carlo models. From the event shape distributions we extract the strong coupling αs and test its evolution with energy scale. The results are consistent with the running of αs expected from QCD. Combining all data, the value of αs(MZ) is determined to be αs(MZ) = 0.1191 ± 0.0005 (stat.) ± 0.0010 (expt.) ± 0.0011 (hadr.) ± 0.0044 (theo.) . The energy evolution of the moments is also used to determine a value of αs with slightly larger errors: αs(MZ) = 0.1223±0.0005(stat.)±0.0014(expt.)±0.0016(hadr.) −0.0036(theo.). (Submitted to European Physical Journal C) The OPAL Collaboration G.Abbiendi, C.Ainsley, P.F. Åkesson , G.Alexander, J. Allison, P.Amaral, G.Anagnostou, K.J.Anderson, S.Asai, D.Axen, I. Bailey, E. Barberio, T.Barillari, R.J. Barlow, R.J. Batley, P. Bechtle, T.Behnke, K.W.Bell, P.J. Bell, G.Bella, A.Bellerive, G.Benelli, S. Bethke, O.Biebel, O.Boeriu, P. Bock, M.Boutemeur, S. Braibant, R.M.Brown, H.J. Burckhart, S. Campana, P.Capiluppi, R.K.Carnegie, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, C.Ciocca, A.Csilling, M.Cuffiani, S.Dado, A.De Roeck, E.A.De Wolf, K.Desch, B.Dienes, M.Donkers, J.Dubbert, E.Duchovni, G.Duckeck, I.P.Duerdoth, E. Etzion, F. Fabbri, P. Ferrari, F. Fiedler, I. Fleck, M.Ford, A. Frey, P.Gagnon, J.W.Gary, C.Geich-Gimbel, G.Giacomelli, P.Giacomelli, M.Giunta, J.Goldberg, E.Gross, J.Grunhaus, M.Gruwé, P.O.Günther, A.Gupta, C.Hajdu, M.Hamann, G.G.Hanson, A.Harel, M.Hauschild, C.M.Hawkes, R.Hawkings, R.J.Hemingway, G.Herten, R.D.Heuer, J.C.Hill, K.Hoffman, D.Horváth, P. Igo-Kemenes, K. Ishii, H. Jeremie, P. Jovanovic, T.R. Junk, J.Kanzaki, D.Karlen, K.Kawagoe, T.Kawamoto, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, S.Kluth, T.Kobayashi, M.Kobel, S.Komamiya, T.Krämer, P.Krieger, J. von Krogh, T.Kuhl, M.Kupper, G.D. Lafferty, H. Landsman, D. Lanske, D. Lellouch, J. Letts, L. Levinson, J. Lillich, S.L. Lloyd, F.K. Loebinger, J. Lu, A. Ludwig, J. Ludwig, W.Mader, S.Marcellini, A.J.Martin, G.Masetti, T.Mashimo, P.Mättig, J.McKenna, R.A.McPherson, F.Meijers, W.Menges, F.S.Merritt, H.Mes, N.Meyer, A.Michelini, S.Mihara, G.Mikenberg, D.J.Miller, W.Mohr, T.Mori, A.Mutter, K.Nagai, I. Nakamura, H.Nanjo, H.A.Neal, R.Nisius, S.W.O’Neale, A.Oh, M.J.Oreglia, S.Orito, C. Pahl, G. Pásztor, J.R.Pater, J.E. Pilcher, J. Pinfold, D.E.Plane, O. Pooth, M.Przybycień, A.Quadt, K.Rabbertz, C.Rembser, P.Renkel, J.M.Roney, A.M.Rossi, Y.Rozen, K.Runge, K. Sachs, T. Saeki, E.K.G. Sarkisyan , A.D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, T. Schörner-Sadenius , M. Schröder, M. Schumacher, R. Seuster , T.G. Shears, B.C. Shen, P. Sherwood, A. Skuja, A.M. Smith, R. Sobie, S. Söldner-Rembold, F. Spano, A. Stahl, D. Strom, R. Ströhmer, S. Tarem, M.Tasevsky , R.Teuscher, M.A.Thomson, E.Torrence, D.Toya, P.Tran, I. Trigger, Z. Trócsányi, E.Tsur, M.F.Turner-Watson, I. Ueda, B.Ujvári, C.F.Vollmer, P.Vannerem, R.Vértesi, M.Verzocchi, H.Voss, J. Vossebeld, C.P.Ward, D.R.Ward, P.M.Watkins, A.T.Watson, N.K.Watson, P.S.Wells, T.Wengler, N.Wermes, G.W.Wilson, J.A.Wilson, G.Wolf, T.R.Wyatt, S.Yamashita, D. Zer-Zion, L. Zivkovic School of Physics and Astronomy, 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

~OPAL Collaboration! School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, United Kingdom Dipartimento di Fisica dell’ Universita ` di Bologna and INFN, I-40126 Bologna, Italy Physikalisches Institut, Universita ̈t Bonn, D-53115 Bonn, Germany Department of Physics, University of California, Riverside, California 92521, USA Cavendish Laboratory, Cambridge CB3 0HE, United Kingdom Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, Ottawa, Ontario, Canada K1S 5B6 CERN, European Organisation for Nuclear Research, CH-1211 Geneva 23, Switzerland Enrico Fermi Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA Fakultät für Physik, Albert-Ludwigs-Universita ̈ Freiburg, D-79104 Freiburg, Germany Physikalisches Institut, Universita ̈t Heidelberg, D-69120 Heidelberg, Germany Department of Physics, Indiana University, Bloomington, Indiana 47405, USA Queen Mary and Westfield College, University of London, London E1 4NS, United Kingdom Technische Hochschule Aachen, III Physikalisches Institut, Sommerfeldstrasse 26-28, D-52056 Aachen, Germany University College London, London WC1E 6BT, United Kingdom Department of Physics, Schuster Laboratory, The University, Manchester M13 9PL, United Kingdom Department of Physics, University of Maryland, College Park, Maryland 20742, USA Laboratoire de Physique Nucle ́aire, Universitéde Montréal, Montréal, Québec, Canada H3C 3J7 University of Oregon, Department of Physics, Eugene, Oregon 97403, USA CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom 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 113-0033, Jap and Kobe University, Kobe 657-8501, Japan Particle Physics Department, Weizmann Institute of Science, Rehovot 76100, Israel Universität Hamburg/DESY, Institut fu ̈r Experimentalphysik, Notkestrasse 85, D-22607 Hamburg, Germany University of Victoria, Department of Physics, P O Box 3055, Victoria BC, Canada V8W 3P6

The mass and width of the W boson are measured using ee → WW events from the data sample collected by the OPAL experiment at LEP at centre-of-mass energies between 170GeV and 209GeV. The mass (mW) and width (ΓW) are determined using direct reconstruction of the kinematics of WW → qq̄lν and WW → qq̄qq̄ events. When combined with previous OPAL measurements using WW → lνlν events and the dependence on mW of the WW production cross-section at threshold, the results are determined to be mW = 80.415± 0.042 ± 0.030 ± 0.009 GeV ΓW = 1.996 ± 0.096 ± 0.102± 0.003 GeV where the first error is statistical, the second systematic and the third due to uncertainties in the value of the LEP beam energy. By measuring mW with several different jet algorithms in the qq̄qq̄ channel, a limit is also obtained on possible final-state interactions due to colour reconnection effects in WW → qq̄qq̄ events. The consistency of the results for the W mass and width with those inferred from other electroweak parameters provides an important test of the Standard Model of electroweak interactions. This paper is dedicated to the memory of Steve O’Neale Submitted to Eur. Phys. J. C.

The inclusive production of D (cid:3)(cid:6) mesons in photon-photon collisions has been measured using the OPAL detector at LEP at e + e − centre-of-mass energies p s ee of 183 and 189 GeV. The D (cid:3) + mesons are reconstructed in their decay to D 0 (cid:25) + with the D 0 observed in the two decay modes K − (cid:25) + and K − (cid:25) + (cid:25) − (cid:25) + . After background subtraction, 100 : 4 (cid:6) 12 : 6 (stat) D (cid:3)(cid:6) mesons have been selected in events without observed scattered beam electron (\anti-tagged") and 29 : 8 (cid:6) 5 : 9 (stat) D (cid:3)(cid:6) mesons in events where one beam electron is scattered into the detector (\single-tagged"). Direct and single-resolved events are studied separately. Di(cid:11)erential cross-sections d (cid:27)= d p D (cid:3) T and d (cid:27)= d j (cid:17) D (cid:3) j as functions of the D (cid:3)(cid:6) transverse momentum p D (cid:3) T and pseudorapidity (cid:17) D (cid:3) are presented in the kinematic region 2 GeV < p D (cid:3) T < 12 GeV and j (cid:17) D (cid:3) j < 1 : 5. They are compared to next-to-leading order (NLO) perturbative QCD calculations. The total cross-section for the process e + e − ! e + e − cc where the charm quarks are produced in the collision of two quasi-real photons is measured to be averaged