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1. Preparatory procedure and equipment for the European x-ray free electron laser cavity implementation

Author: D. Reschke, R. Bandelmann, T. Buettner, K. Escherich, A. Goessel, B. v.d.Horst, J. Iversen, D. Klinke, G. Kreps, N. Krupka, L. Lilje, A. Matheisen, W.-D. Moeller, H. Morales Zimmermann, C. Mueller, B. Petersen, D. Proch, M. Schmoekel, N. Steinhau-Kuehl, J.-H. Thie, H. Weise, H. Weitkaemper, R. Carcagno, T. N. Khabiboulline, S. Kotelnikov, A. Makulski, J. Nogiec, R. Nehring, M. Ross, and W. Schappert
Subjects: Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: The European x-ray free electron laser is under construction at Deutsches Elektronen-Synchrotron (DESY). The electron beam energy of up to 17.5 GeV will be achieved by using superconducting accelerator technology. Final prototyping, industrialization, and new infrastructure are the actual challenges with respect to the accelerating cavities. This paper describes the preparation strategy optimized for the cavity preparation procedure in industry. For the industrial fabrication and preparation, several new hardware components have been already developed at DESY. The design and construction of a semiautomated rf-measurement machine for dumbbells and end groups are described. In a collaboration among FNAL, KEK, and DESY, an automatic cavity tuning machine has been designed and four machines are under construction. The functionality of these machines with special attention to safety aspects is described in this paper. A new high pressure rinsing system has been developed and is operational.
Published: 2010
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2. Record high-gradient SRF beam acceleration at Fermilab

Author: D Broemmelsiek, B Chase, D Edstrom, E Harms, J Leibfritz, S Nagaitsev, Y Pischalnikov, A Romanov, J Ruan, W Schappert, V Shiltsev, R Thurman-Keup, and A Valishev
Subjects: linear accelerator, superconducting RF, electron source, beam diagnostics, Science, Physics, QC1-999
Abstract: Many modern and future particle accelerators employ high gradient superconducting RF (SRF) to generate beams of high energy, high intensity and high brightness for research in high energy and nuclear physics, basic energy sciences, etc. In this paper we report the record performance large-scale SRF system with average beam accelerating gradient matching the International Linear Collider (ILC) specification of 31.5 MV m ^−1 . Design of the eight cavity 1.3 GHz SRF cryomodule, its performance without the beam and results of the system commissioning with high intensity electron beam at Fermilab Accelerator Science and Technology (FAST) facility are presented. We also briefly discuss opportunities for further beam studies and tests at FAST including those on even higher gradient and more efficient SRF acceleration, as well as exploration of the system performance with full ILC-type beam specifications.
Published: 2018
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3. Record High-Gradient SRF Beam Acceleration at Fermilab

Author: Vladimir Shiltsev, Alexander Valishev, Brian Chase, J. Leibfritz, Jinhao Ruan, Randy Thurman-Keup, Elvin Harms, Yu. Pischalnikov, Alexander S. Romanov, W. Schappert, Daniel Broemmelsiek, Sergei Nagaitsev, and Dean Edstrom
Subjects: Physics, Accelerator Physics (physics.acc-ph), Brightness, International Linear Collider, 010308 nuclear & particles physics, business.industry, General Physics and Astronomy, FOS: Physical sciences, Particle accelerator, 01 natural sciences, law.invention, Acceleration, Optics, law, Cryomodule, 0103 physical sciences, Cathode ray, Physics::Accelerator Physics, Physics - Accelerator Physics, Fermilab, 010306 general physics, business, Beam (structure)
Abstract: Many modern and future particle accelerators employ high gradient superconducting RF (SRF) to generate beams of high energy, high intensity and high brightness for research in high energy and nuclear physics, basic energy sciences, etc. In this paper we report the record performance large-scale SRF system with average beam accelerating gradient matching the ILC specification of 31.5MV/m. Design of the eight cavity 1.3 GHz SRF cryomodule, its performance without the beam and results of the system commissioning with high intensity electron beam at FAST (Fermilab Accelerator Science and Technology) facility are presented. We also briefly discuss opportunities for further beam studies and tests at FAST including those on even higher gradient and more efficient SRF acceleration., Comment: 18 pages, 9 figures
Published: 2018
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4. Challenges and Design of the Transport Solenoid for the Mu2e Experiment at Fermilab

Author: N. Andreev, M.J. Lamm, T.J. Peterson, Thomas H. Nicol, M.A. Tartaglia, J. P. Miller, D.F. Orris, R. Coleman, D. Evbota, Vitaly Pronskikh, N. Dhanaraj, W. Schappert, V.V. Kashikhin, V. Lombardo, T. Page, R. Wands, M. L. Lopes, Sandor Feher, Sergey Cheban, and Giorgio Ambrosio
Subjects: Coupling, Physics, Physics::Instrumentation and Detectors, Aperture, Mechanical engineering, Solenoid, Superconducting magnet, Physics::Classical Physics, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Nuclear magnetic resonance, Electromagnetic coil, Magnet, Mu2e, Physics::Accelerator Physics, Fermilab, Electrical and Electronic Engineering
Abstract: The Fermilab Mu2e experiment seeks to measure the rare process of direct muon to electron conversion in the field of a nucleus. The magnet system for this experiment is made of three warm-bore solenoids: the Production Solenoid (PS), the Transport Solenoid (TS), and the Detector Solenoid (DS). The TS is an “S-shaped” solenoid set between the other bigger solenoids. The Transport Solenoid has a warm-bore aperture of 0.5 m and field between 2.5 and 2.0 T. The PS and DS have, respectively warm-bore aperture of 1.5 m and 1.9 m, and peak field of 4.6 T and 2 T. In order to meet the field specifications, the TS starts inside the PS and ends inside the DS. The strong coupling with the adjacent solenoids poses several challenges to the design and operation of the Transport Solenoid. The coil layout has to compensate for the fringe field of the adjacent solenoids. The quench protection system should handle all possible quench and failure scenarios in all three solenoids. The support system has to be able to withstand very different forces depending on the powering status of the adjacent solenoids. In this paper, the conceptual design of the Transport Solenoid is presented and discussed focusing on these coupling issues and the proposed solutions.
Published: 2014

5. Optical transition radiation imaging of intense proton beams at FNAL

Author: W. Schappert, V.E. Scarpine, G.R. Tassotto, and Alex H. Lumpkin
Subjects: Physics, Nuclear and High Energy Physics, Proton, business.industry, Optical transition, Detector, Radiation, Optics, Nuclear Energy and Engineering, Antiproton, Physics::Accelerator Physics, Electrical and Electronic Engineering, Particle radiation, business, Beam (structure), Fermi Gamma-ray Space Telescope
Abstract: Initial results are presented of a prototype optical transition radiation (OTR) detector under development at Fermi National Accelerator Laboratory. The purpose of this prototype detector is to evaluate the feasibility of using OTR imaging of intense proton (or antiproton) beams in transport lines for beam position and shape measurements. A secondary purpose is to develop experience in designing, constructing and operating a camera and optics system in high radiation environments. Measurements are made of 120 GeV proton beams with intensities up to 4.7/spl times/10/sup 12/ particles. Data are presented of OTR with titanium and aluminum foils.
Published: 2004

6. LORENTZ FORCE COMPENSATION FOR LONG PULSES IN SRF CAVITIES

Author: Y Pischalnikov, G Cancelo, B Chase, D Crawford, D Edstrom, E Harms, R Kostin, N Solyak, and W Schappert
Published: 2012
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7. Measurement of $$\Gamma (Z^0 \to b\bar b)/\Gamma (Z^0 \to hadrons)$$ using impact parameters and leptons

Author: R. Lahmann, D. C. Imrie, J. C. Clayton, B. C. Shen, G. P. Siroli, J. King, A. K. Honma, Christoph Schwick, W. G. Scott, Gideon Bella, H. J. Burckhart, M. Jones, Jacqueline Batley, G. A. Snow, C. P. Ward, M. J. Pearce, Horst Breuker, Margret Fincke-Keeler, D. L. Rees, M. J. Losty, Otmar Biebel, P. Igo-Kemenes, C. Jui, J. Hart, C. Sbarra, S. Barnett, Claude Leroy, A. Astbury, J. P. Pansart, J. D. Gillies, P. Pfister, R. Bartoldus, H. Jeremie, U. Müller, James Pinfold, G. E. Richards, D. Pitman, A. J. Martin, F. C. Grant, M. H. Lehto, D. G. Charlton, D. L. Wagner, R. J. Barlow, R. E. Hughes-Jones, U. Maur, D. Hochman, D. G. Fong, H. O. Ogren, Michael Dittmar, G. Yekutieli, D. J. Miller, Christoph Geich-Gimbel, G. Beaudoin, C. K. Hargrove, N. I. Geddes, Matthias Schröder, H. Lafoux, N. Paz-Jaoshvili, J. Steuerer, J. Gascon, H. von der Schmitt, T. G. Shears, B. Boden, K. Stephens, J. R. McNutt, R.J. Akers, J. Lauber, E. do Couto e Silva, A. Buijs, D. M. Strom, C. Stegmann, H. Takeda, D. M. Gingrich, D. E. Plane, P. Bentkowski, A. A. Carter, Roger Jones, R. Van Kooten, M. G. Rison, T. J. McMahon, B. Poli, F. G. Oakham, G. M. Dallavalle, M. Hansroul, Madjid Boutemeur, E. Lefebvre, J. W. Gary, Marcello Mannelli, J. E. Duboscq, H. Deng, R. Humbert, Shlomo Dado, Tohru Takeshita, J. Schwiening, R. K. Carnegie, F. X. Gentit, B. Fabbro, O. Schaile, P. Berlich, J. A. Wilson, F. Odorici, J. E. Conboy, B. Panzer-Steindel, R. Kowalewski, R. Yaari, D. J.P. Dumas, R. J. Hemingway, Georges Azuelos, P. G. Estabrooks, R. K. Keeler, P. M. Watkins, V. Gibson, S. Bethke, P. Scharff-Hansen, G. Quast, J. M. Lorah, W. Schappert, P. Kroll, Marco Cuffiani, John Baines, X. C. Lou, Silvia Arcelli, W. R. Gibson, A. M. Rossi, C. H. Shepherd-Themistocleous, P. Jovanovic, T. Tsukamoto, W. Mohr, J. F. Kral, Austin Ball, H. M. Fischer, M. A. Whallev, K. W. Bell, Max Weber, D. Menszner, Randall Sobie, G. D. Lafferty, S. L. Chu, A. Beck, J. C. Hill, A. Michelini, H. Mes, Norbert Wermes, J. von Krogh, I. P. Duerdoth, A. C. Janissen, J. M. Roney, E. Heflin, Sherry Towers, P. S. Wells, Misao Sasaki, R. J. Homer, M. Hauschild, Alessandro Montanari, R. M. Brown, T. Kawamoto, A. M. Smith, P. M. Hattersley, J. Banks, Lorne Levinson, G. Vasseur, Dave Robinson, Gideon Alexander, P. A. Elcombe, Giora Mikenberg, C. Markus, P. Paschievici, Terry Richard Wyatt, B. Lorazo, D. R. Ward, L. A. del Pozo, C. Y. Chang, M. F. Turner, B. W. Kennedy, T. W. Pritchard, E. Torrente-Lujan, G. Transtromer, Paolo Capiluppi, Kiyotomo Kawagoe, John Hobbs, C. Moisan, R. D. Heuer, M. Coupland, Andris Skuja, G. A. Beck, Fabrizio Fabbri, Achim Stahl, S. Orito, M. Rosvick, J. Becker, P. Teixeira-Dias, D. Van den plas, P. Weber, F. S. Merritt, F. Scharf, Tetsuro Mashimo, G. J. VanDalen, R. Mir, Gregor Herten, D. R. Rust, C. Wahl, B. Schmitt, B. Wilkens, A. Skillman, A. M. Lee, J. E. Pilcher, W. Gorn, A. Gaidot, T. Wlodek, M. Sproston, G. Giacomelli, J. A. McKenna, M. J. Oreglia, N. Tesch, A. Dieckmann, A. D. Schaile, V. H. Winterer, P. Schenk, J. R. Carter, P. F. Harrison, G. N. Patrick, Stephen Lloyd, M. Tecchio, M. S. Dixit, Ehud Duchovni, M. Jimack, H. Ihssen, Frans Meijers, S. W. Gensler, S. J. Hillier, T. Kobayashi, P. E.L. Clarke, H. Przysiezniak, M. Fierro, M. Yurko, S. A. Robins, J. P. Martin, P. W. Jeffreys, S. De Jong, P. Bright-Thomas, S. W. O'Neale, M. A. Thomson, K. J. Anderson, J. G. Layter, T. Hilse, O. Runolfsson, P. Poffenberger, C. Beeston, Claudio Grandi, D. A. Hinshaw, T. Behnke, D. Axen, A. Jawahery, Peter Sherwood, I. J. Bloodworth, R. W. Springer, Alexander Wagner, J. Hagemann, J. Ludwig, K. Runge, P. Bock, G. Duckeck, R. Ströhmer, G. T. Zorn, H. M. Bosch, Wolfram Dietrich Zeuner, A. Yeaman, M. Settles, M. Foucher, N. K. Watson, G. W. Wilson, D. Karlen, C. Burgard, C. M. Hawkes, M. Cooper, Erez Etzion, Daniel Lellouch, Takehiko Mori, Stefan Kluth, Shlomit Tarem, S. Rossberg, C. J. Oram, R. P. Middleton, J. Goldberg, B. Nellen, P. Leblanc, M. Morii, T. J. Smith, Peter R Hobson, H. G. Evans, M. J. Goodrick, I. Cohen, P. Routenburg, Gunter Wolf, P. Mättig, Sachio Komamiya, N. J. Tesilian, E. Ros, A. T. Watson, S. Wotton, T. P. Kokott, A. Luig, Paul Kyberd, F. K. Loebinger, A. Rollnik, R. Giacomelli, J. Mildenberger, Harold Nguyen, Gordon H. Hanson, M. W. Redmond, John Allison, R. G. Kellogg, D. S. Koetke, Stefano Marcellini, and James Letts
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Astrophysics::High Energy Astrophysical Phenomena, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Elementary particle, Bottom quark, Charm quark, Nuclear physics, High Energy Physics::Experiment, Production (computer science), Impact parameter, Engineering (miscellaneous), Particle Physics - Experiment, Bar (unit)
Abstract: A measurement of$\Gamma _{b\bar b} /\Gamma _{had} \equiv \Gamma (Z^0 \to b\bar b)/\Gamma (Z^0 \to hadrons)$ is presented using a “mixed tag” method involving the identification of$Z^0 \to b\bar b$ events by two different techniques. The first uses the large impact parameter of tracks emerging from the decay ofb-flavoured hadrons and the second their semi-leptonic decay. The identification efficiencies are measured from the data using all possible combinations of the two tags in opposite hemispheres. The method is therefore insensitive to Monte Carlo modelling of bottom quark production and ofb-flavoured hadron production and decay properties, and depends only weakly on the simulation of the detector. The data sample collected by OPAL at LEP in 1990 and 1991 is considered. The result is: $$\frac{{\Gamma _{b\bar b} }}{{\Gamma _{had} }} = 0.218 \pm 0.006(stat) \pm 0.007(syst) \pm 0.007(\Gamma _{c\bar c} /\Gamma _{had} ),$$ where the systematic uncertainty due to the charm quark partial width has been separated from the other systematic uncertainties. Combination with previous OPAL measurements gives: $$\frac{{\Gamma _{b\bar b} }}{{\Gamma _{had} }} = 0.220 \pm 0.004(stat) \pm 0.006(syst) \pm 0.006(\Gamma _{c\bar c} /\Gamma _{had} ),$$
Published: 1994

8. Measurement of the photon structure functionF 2 ? in the reactione + e ??e + e ?+hadrons at LEP

Author: James Pinfold, D. G. Fong, J. Gascon, H. von der Schmitt, Otmar Biebel, G. E. Richards, D. G. Charlton, D. L. Wagner, Matthias Schröder, Marcello Mannelli, J. E. Duboscq, R. W.L. Jones, Andris Skuja, Tetsuro Mashimo, W. Gorn, H. Deng, R. Humbert, M. Yurko, P. Scharff-Hansen, A. M. Smith, G. Vasseur, B. Lorazo, Kiyotomo Kawagoe, J. Steuerer, Erez Etzion, H. Lafoux, N. Paz-Jaoshvili, Norbert Wermes, Sherry Towers, Silvia Arcelli, I. J. Bloodworth, M. Settles, S. A. Robins, P. W. Jeffreys, T. Kobayashi, Gideon Bella, Stefan Kluth, P. Igo-Kemenes, M. Foucher, H. J. Burckhart, P. Bright-Thomas, T. Kawamoto, C. Y. Chang, M. F. Turner, Gregor Herten, C. Wahl, B. Wilkens, D. A. Hinshaw, Jacqueline Batley, Tohru Takeshita, J. G. Layter, G. W. Wilson, D. Karlen, C. Burgard, H. Jeremie, O. Schaile, Shlomit Tarem, J. J. Ward, G. J. VanDalen, J. C. Clayton, M. A. Thomson, M. Hansroul, P. Weber, S. Rossberg, C. J. Oram, R. E. Hughes-Jones, U. Maur, J. Mildenberger, Harold Nguyen, Georges Azuelos, J. E. Pilcher, Shlomo Dado, T. Behnke, V. Gibson, J. F. Kral, K. W. Bell, N. I. Geddes, C. H. Shepherd-Themistocleous, R. P. Middleton, M. J. Pearce, Horst Breuker, Max Weber, M. W. Redmond, J. C. Hill, R. J. Homer, X. C. Lou, R. J. Barlow, R. Yaari, P. E.L. Clarke, M. Hauschild, B. C. Shen, P. S. Wells, E. do Couto e Silva, T. W. Pritchard, J. Goldberg, H. Przysiezniak, M. Fierro, J. Banks, S. Bethke, A. K. Honma, W. G. Scott, W. R. Gibson, E. Lefebvre, Marco Cuffiani, J. P. Martin, C. Moisan, B. Nellen, J. W. Gary, F. Odorici, N. J. Tresilian, Terry Richard Wyatt, G. A. Beck, A. T. Watson, P. Mättig, C. Markus, R. G. Kellogg, A. Astbury, Achim Stahl, P. Paschievici, P. Leblanc, S. De Jong, P. Teixeira-Dias, D. S. Koetke, R. D. Heuer, Stefano Marcellini, U. Müller, C. M. Hawkes, M. Coupland, M. Cooper, J. A. McKenna, M. J. Losty, James Letts, Fabrizio Fabbri, D. Van den plas, B. Fabbro, A. J. Martin, Daniel Lellouch, S. L. Chu, T. Hilse, B. Panzer-Steindel, H. Mes, Paul Kyberd, F. K. Loebinger, Takehiko Mori, A. Beck, H. G. Evans, I. P. Duerdoth, J. Allison, D. Pitman, M. J. Goodrick, G. D. Lafferty, P. F. Harrison, I. Cohen, M. H. Lehto, G. Duckeck, R. Ströhmer, B. Schmitt, E. Heflin, C. Jui, O. Runolfsson, M. Jones, A. Rollnik, P. Poffenberger, R. Giacomelli, C. K. Hargrove, G. Mikenberg, Madjid Boutemeur, Gunter Wolf, R. M. Brown, G. A. Snow, C. P. Ward, P. M. Hattersley, T. G. Shears, T. J. Smith, R. J. Sobie, D. L. Rees, Lorne Levinson, P. G. Estabrooks, R. K. Keeler, K. Stephens, D. M. Gingrich, A. M. Rossi, C. Beeston, Margret Fincke-Keeler, R.J. Akers, Claudio Grandi, J. R. McNutt, John Hobbs, B. W. Kennedy, Gilles Beaudoin, M. Tecchio, S. Wotton, E. Torrente-Lujan, P. Berlich, G. T. Zorn, P. M. Watkins, V. H. Winterer, Claude Leroy, J. P. Pansart, T. Tsukamoto, R. Lahmann, D. R. Rust, F. C. Grant, D. C. Imrie, Ehud Duchovni, M. A. Whalley, D. E. Plane, M. Sasaki, P. Bentkowski, G. M. Dallavalle, A. M. Lee, M. Jimack, A. Buijs, G. Quast, John Baines, D. M. Strom, C. Stegmann, H. Ihssen, D. J.P. Dumas, P. Pfister, S. W. Gensler, S. J. Hillier, B. Boden, H. M. Bosch, Wolfram Dietrich Zeuner, B. Poli, D. R. Ward, G. Transtromer, G. P. Siroli, J. King, H. M. Fischer, A. Michelini, R. Kowalewski, A. C. Janissen, S. W. O'Neale, S. Barnett, Christoph Schwick, Gideon Alexander, D. Hochman, Paolo Capiluppi, J. R. Carter, D. Axen, K. J. Anderson, A. Jawahery, Peter Sherwood, R. W. Springer, Alexander Wagner, J. Hagemann, J. Ludwig, K. Runge, P. Bock, S. Orito, M. Rosvick, M. Morii, Peter R Hobson, R. Mir, P. Routenburg, M. J. Oreglia, F. S. Merritt, J. von Krogh, Dave Robinson, G. N. Patrick, L. A. del Pozo, C. Sbarra, R. Bartoldus, Michael Dittmar, G. Yekutieli, H. O. Ogren, A. Yeaman, Christoph Geich-Gimbel, A. A. Carter, J. Kroll, R. Van Kooten, S. L. Lloyd, N. K. Watson, F. X. Gentit, J. E. Conboy, Sachio Komamiya, M. G. Rison, T. J. McMahon, J. Schwiening, E. Ros, R. K. Carnegie, J. A. Wilson, T. P. Kokott, A. Luig, W. Schappert, J. M. Roney, J. M. Lorah, J. Lauber, W. Mohr, H. Takeda, F. G. Oakham, R. J. Hemingway, P. Jovanovic, Austin Ball, D. Menszner, Alessandro Montanari, J. Hart, J. D. Gillies, D. J. Miller, P. A. Elcombe, J. Becker, F. Scharf, A. Skillman, A. Gaidot, T. Wlodek, M. Sproston, N. Tesch, A. Dieckmann, G. G. Hanson, G. Giacomelli, A. D. Schaile, P. Schenk, M. S. Dixit, and Frans Meijers
Subjects: Quantum chromodynamics, Quark, Physics, Particle physics, Photon, Physics and Astronomy (miscellaneous), High Energy Physics::Phenomenology, Hadron, Perturbative QCD, Vector meson dominance, Elementary particle, Photon structure function, Nuclear physics, High Energy Physics::Experiment, Nuclear Experiment, Engineering (miscellaneous)
Abstract: We present measurements of the hadronic photon structure functionF2γ(x), in twoQ2 ranges with mean values of 5.9 GeV2 and 14.7 GeV2. The data were taken by the OPAL experiment at LEP, with$\sqrt s$ close to theZ0 mass and correspond to an integratede+e− luminosity of 44.8 pb−1. In the context of a QCD-based model we find the quark transverse momentum cutoff separating the vector meson dominance (VMD) and perturbative QCD regions to be 0.27±0.10 GeV. We confirm that there is a significant pointlike component of the photon when the probe photon hasQ2>4 GeV2. Our measurements extend to lower values ofx than any previous experiment, and no increase ofF2γ(x) is observed.
Published: 1994

9. Multiplicity and transverse momentum correlations in multihadronic final states in e+e− interactions at √s = 91.2 GeV

Author: J. W. Gary, H. O. Ogren, Sachio Komamiya, Christoph Geich-Gimbel, Theodoros Geralis, Carla Sbarra, I. J. Bloodworth, G. Quast, T. P. Kokott, A. Luig, S. L. Lloyd, F. X. Gentit, T. R. Wyatt, M. Settles, J. E. Conboy, M. Tecchio, R. J. Barlow, G. Mikenberg, B. C. Shen, M. Foucher, S. L. Chu, J. D. Gillies, M. Jimack, Siegfried Bethke, M. Hauschild, W. G. Scott, P. Weber, C. Jui, Tohru Takeshita, Georges Azuelos, M. Fierro, C. M. Hawkes, K. W. Bell, Norbert Wermes, J. C. Hill, S. A. Wotton, A. H. Ball, Silvia Arcelli, G. W. Wilson, M. J. Losty, J. Pinfold, C. Schwick, C. Markus, M. Jones, P. Paschievici, J.A. Lauber, D. G. Fong, G. A. Snow, C. P. Ward, J. M. Roney, J. Gascon, J. Goldberg, A. Skillman, D. J. Miller, Kiyotomo Kawagoe, P. Igo-Kemenes, Paul Fraser Harrison, B. Boden, D. L. Rees, G. Duckeck, A. D. Schaile, P. S. Wells, J. Schwiening, B. Nellen, B. Poli, Z. Li, R. G. Kellogg, Daniel Lellouch, P. Leblanc, H. Jeremie, A. Gaidot, D. S. Koetke, F. S. Merritt, Takehiko Mori, A. T. Watson, R. E. Hughes-Jones, U. Maur, T. Hilse, V. H. Winterer, T. Wlodek, M. J. Cooper, M. Sproston, R.J. Akers, W. R. Gibson, V. Gibson, Marcello Mannelli, J. E. Duboscq, D. Axen, H. G. Evans, Stefano Marcellini, M. Morii, N. Tesch, A. Dieckmann, Peter R Hobson, James Letts, A. Jawahery, N. K. Watson, M. J. Goodrick, I. Cohen, J. A. McKenna, Andris Skuja, E. do Couto e Silva, R. J. Hemingway, Shlomo Dado, A. M. Lee, G. D. Lafferty, Tetsuro Mashimo, R. Kowalewski, Claudio Grandi, D. Pitman, D.L. Wagner, M. Yurko, A. Beck, Michael Schulz, P. Jovanovic, P. W. Jeffreys, J. M. Lorah, Madjid Boutemeur, C. Darling, X. C. Lou, E. Heflin, Matthias Schröder, T. Kobayashi, R. Yaari, P. E. L. Clarke, Robert Lahmann, R. W. Springer, W. Mohr, A. M. Rossi, Richard Keeler, R. M. Brown, P. Mättig, J. Mildenberger, Harold Nguyen, Marco Cuffiani, P. G. Estabrooks, C. J. Oram, T. W. Pritchard, W. Gorn, Gideon Alexander, Paolo Capiluppi, Gordon H. Hanson, Alessandro Montanari, T. Tsukamoto, D. C. Imrie, Lorne Levinson, H. von der Schmitt, A. Yeaman, N. I. Geddes, J. Ludwig, K. Runge, P. Bock, P. A. Elcombe, Erez Etzion, Ehud Duchovni, R. Mir, H. M. Fischer, B. W. Kennedy, P. M. Watkins, H. Lafoux, J. J. Ward, David Robinson, M. A. Thomson, Stefan Kluth, Shlomit Tarem, A. Michelini, A. Wagner, J. Hagemann, A. C. Janissen, H. Ihssen, M. Rosvick, P. Scharff-Hansen, F. K. Loebinger, A. Astbury, S. Rossberg, Gilles Beaudoin, E. Torrente-Lujan, N. Paz-Jaoshvili, Gregor Herten, S. A. Robins, S. W. Gensler, R. P. Middleton, F. Scharf, C. Wahl, M. W. Redmond, D. M. Gingrich, S. J. Hillier, H. Mes, G. P. Siroli, J. King, Peter Sherwood, D. A. Hinshaw, A. M. Smith, A. Rollnik, R. Giacomelli, B. Wilkens, J. R. Carter, G. Vasseur, B. Lorazo, Pedro Teixeira-Dias, J. Kroll, H. Takeda, M. Fincke-Keeler, R. D. Heuer, F. G. Oakham, J. Allison, P. Routenburg, G. T. Zorn, P. Kyberd, H. M. Bosch, J. E. Pilcher, Wolfram Dietrich Zeuner, P.A. Hart, Eduardo Ros, John Hart, U. Müller, R. Sobie, A. J. Martin, P. M. Hattersley, T. Behnke, C. K. Hargrove, D. E. Plane, P. Poffenberger, M. J. Pearce, P. Bentkowski, G. M. Dallavalle, O. Runolfsson, D. J.P. Dumas, T. J. McMahon, R. K. Carnegie, J. A. Wilson, W. Schappert, J. G. Layter, Michael Dittmar, G. Yekutieli, A. A. Carter, S. J. De Jong, M. G. Rison, M. F. Turner, S. Barnett, D. Hochman, J. von Krogh, K. Stephens, J. R. McNutt, L. A. del Pozo, G. Giacomelli, P. Schenk, M. S. Dixit, Frans Meijers, D. R. Ward, G. Transtromer, G. J. VanDalen, J. C. Clayton, M. Coupland, J.P. Martin, H. Przysiezniak, Otmar Biebel, G. E. Richards, D. G. Charlton, J. K. Becker, H. Deng, R. Humbert, Paolo Giacomelli, M. Hansroul, C. H. Shepherd-Themistocleous, R. J. Homer, C. Moisan, G. A. Beck, Sherry Towers, T. Kawamoto, B. Schmitt, H-C. Schultz-Coulon, A. Stahl, R. W. L. Jones, P. Pfister, S. Orito, P. Le Du, B. Fabbro, Gideon Bella, H. J. Burckhart, Jacqueline Batley, M. J. Oreglia, A. K. Honma, C. Y. Chang, G. N. Patrick, C. Burgard, J. Steuerer, S. W. O'Neale, K. J. Anderson, Raimund Ströhmer, T. J. Smith, P. Schütz, M. Sasaki, I. P. Duerdoth, E. Lefebvre, F. Odorici, R. Howard, Claude Leroy, D. R. Rust, J. P. Pansart, P.G. Bright-Thomas, F. C. Grant, M. A. Whalley, A. Buijs, D. M. Strom, C. Stegmann, R. Van Kooten, M. H. Lehto, C.J. Beeston, T. G. Shears, Gy. Wolf, P. Berlich, D. Karlen, O. Schaile, N. J. Tresilian, Fabrizio Fabbri, D. Van den plas, and R. Bartoldus
Subjects: Quark, Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Multiplicity (mathematics), Charged particle, Gluon, Nuclear physics, High Energy Physics::Experiment, Parton shower
Abstract: We report a study of forward-backward multiplicity correlations and a measurement of the dependence on charged multiplicity of the mean transverse momentum of charged hadrons, measured with respect to the thrust axis. The study was performed on a high statistics sample of Z(0) decays to multihadronic final states collected by the OPAL Collaboration at LEP. The positive forward-backward multiplicity correlation observed in our inclusive sample can be understood in terms of a superposition of distinct event topologies characterized by a different amount of hard gluon radiation (2-, 3- and 4-jet events) and with different mean multiplicities. The residual positive correlation that we see in a clean 2-jet sample can be interpreted in terms of fragmentation properties of different quark flavours and of the production and decay of resonances. We have compared the observed effects with the predictions of QCD-based parton shower models. The data are well described by the Jetset 7.3 Monte Carlo, while Herwig 5.5 does not satisfactorily reproduce the measured correlations. Hard gluon radiation is also shown to be responsible for the observed increase of about 40% in the mean transverse momentum of produced charged hadrons in the multiplicity range from 10 to 30. The comparison with the results obtained in an analysis of a sample enriched in Z(0) --> b $$($) over bar b events, shows that the presence of heavy flavours does not contribute significantly to the observed effect.
Published: 1994

10. Measurement of $$\Gamma ({\rm Z}^0 \to b\bar b)/\Gamma ({\rm Z}^0 \to hadrons)$$ using leptons

Author: M. Hauschild, P. Singh, Tohru Takeshita, C. Markus, J. Hart, P. Paschievici, R. W. L. Jones, J. D. Gillies, Georges Azuelos, B. Panzer-Steindel, J. F. Kral, Gideon Alexander, Horst Breuker, K. W. Bell, Max Weber, D. J. Miller, J. C. Hill, Paolo Capiluppi, D. Pitman, P. Igo-Kemenes, G. Maringer, M. Jobes, U. Binder, P. E.L. Clarke, J. Steuerer, C. Y. Chang, M. F. Turner, Gideon Bella, H. O. Ogren, Christoph Geich-Gimbel, A. Astbury, F. Lamarche, H. J. Burckhart, Jacqueline Batley, J. Kroll, H. Jeremie, O. Ganel, R. E. Hughes-Jones, U. Maur, P. Taras, P. Scharff-Hansen, A. J. Martin, R. J. Hemingway, M. H. Lehto, Mitsuaki Nozaki, W. J. Collins, Ehud Duchovni, R. Shypit, C. Moisan, J. P. Walker, G. A. Beck, P. Teixeira-Dias, S. L. Lloyd, F. X. Gentit, J. E. Conboy, Silvia Arcelli, A. M. Smith, A. Simon, Otmar Biebel, T. G. Shears, V. Gibson, P. Jovanovic, S. Barnett, H. Ihssen, T. Behnke, Austin Ball, R. Yaari, B. Schmitt, S. W. Gensler, A. Pouladdej, G. E. Richards, D. G. Charlton, D. L. Wagner, G. Vasseur, B. Lorazo, T. W. Pritchard, S. Bethke, D. Menszner, S. J. Hillier, E. do Couto e Silva, C. J. Virtue, Marco Cuffiani, Margret Fincke-Keeler, P. Pfister, Alessandro Montanari, D. Hochman, N. J. Thackray, C. K. Hargrove, T. J. Smith, K. Stephens, P. Berlich, H. Deng, R. Humbert, J. R. McNutt, L. Köpke, J. Goldberg, B. Nellen, James Pinfold, M. Jimack, C. Wahl, F. S. Merritt, S. L. Chu, M. Hansroul, D. G. Fong, J. Gascon, H. von der Schmitt, P. Leblanc, Michael Dittmar, G. Yekutieli, Norbert Wermes, J. E. Pilcher, A. D. Schaile, C. H. Shepherd-Themistocleous, R. J. Homer, D. R. Rust, B. C. Shen, P. A. Elcombe, N. Paz-Jaoshvili, T. Kawamoto, G. Quast, S. W. O'Neale, H. G. Evans, P. F. Harrison, M. J. Goodrick, I. Cohen, R. J. Sobie, S. Orito, R. G. Kellogg, John Baines, V. H. Winterer, G. D. Lafferty, John Hobbs, A. K. Honma, D. S. Koetke, W. G. Scott, M. Rosvick, R. Mir, Marcello Mannelli, J. E. Duboscq, P. D. Acton, Andris Skuja, M. Tecchio, Stefano Marcellini, W. R. Gibson, J. A. McKenna, James Letts, A. A. Carter, P. M. Hattersley, J. W. Gary, M. Yurko, R. Kowalewski, J. Becker, K. J. Anderson, D. R. Ward, G. Transtromer, Tetsuro Mashimo, P. G. Estabrooks, R. K. Keeler, B. Boden, Claude Leroy, J. P. Pansart, B. Poli, G. J. VanDalen, F. Odorici, R. F. McGowan, J. Mildenberger, Harold Nguyen, M. J. Oreglia, J. C. Clayton, P. M. Watkins, W. Gorn, R. Van Kooten, A. Beck, G. A. Bahan, P. W. Jeffreys, P. P. Allport, T. Mouthuy, O. Schaile, N. I. Geddes, C. Jui, F. G. Oakham, J. M. Roney, P. S. Wells, E. Heflin, S. Wotton, A. T. Watson, T. Kobayashi, A. M. Lee, J. Banks, N. J. Tresilian, G. N. Patrick, R. M. Brown, R. D. Heuer, M. Sasaki, J. M. Lorah, Lorne Levinson, M. Coupland, F. C. Grant, M. A. Whalley, Paul Kyberd, F. K. Loebinger, Fabrizio Fabbri, W. Mohr, D. Van den plas, Kiyotomo Kawagoe, H. Mes, A. M. Rossi, Shlomo Dado, Erez Etzion, A. Buijs, D. M. Strom, M. W. Redmond, I. P. Duerdoth, Stefan Kluth, Shlomit Tarem, T. Tsukamoto, B. W. Kennedy, Gilles Beaudoin, A. Rollnik, P. Poffenberger, E. Torrente-Lujan, R. Giacomelli, S. Levegrün, H. M. Fischer, A. Michelini, A. C. Janissen, S. Rossberg, C. J. Oram, G. Mikenberg, A. Gaidot, M. Kuwano, J. von Krogh, T. Wlodek, M. Sproston, R. P. Middleton, P. Routenburg, N. Tesch, A. Dieckmann, D. E. Plane, P. Bentkowski, Dave Robinson, J. R. Carter, G. M. Dallavalle, L. A. del Pozo, S. Schreiber, T. J. McMahon, D. J.P. Dumas, X. C. Lou, J. Schwiening, R. K. Carnegie, J. A. Wilson, P. Bright-Thomas, W. Schappert, P. Weber, R. Lahmann, D. C. Imrie, M. A. Thomson, G. P. Siroli, Christoph Schwick, G. A. Snow, C. P. Ward, D. L. Rees, T. R. Wyatt, R. J. Barlow, H. Przysiezniak, M. J. Losty, M. Fierro, T. Hilse, O. Runolfsson, Claudio Grandi, G. G. Hanson, G. Giacomelli, P. Schenk, M. S. Dixit, Frans Meijers, J. P. Martin, M. Morii, Peter R Hobson, Sachio Komamiya, S. De Jong, E. Ros, T. P. Kokott, Carla Sbarra, J. G. Layter, I. J. Bloodworth, A. Yeaman, N. K. Watson, M. Settles, M. Foucher, G. W. Wilson, D. Karlen, C. Burgard, P. Mättig, C. M. Hawkes, M. Cooper, Daniel Lellouch, Takehiko Mori, D. A. Hinshaw, J. Allison, G. Duckeck, R. Ströhmer, G. T. Zorn, H. M. Bosch, Wolfram Dietrich Zeuner, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, R. W. Springer, Alexander Wagner, J. Hagemann, J. Ludwig, K. Runge, and P. Bock
Subjects: Physics, Nuclear physics, Particle physics, Muon, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Hadron, High Energy Physics::Experiment, Electron, Width ratio, Engineering (miscellaneous), High momentum, Lepton
Abstract: The fraction of $$b\bar b$$ events in hadronicZ 0 decays has been measured from the yield of leptons in the data samples collected by OPAL in 1990 and 1991. A sample enriched in events containing $${\rm Z}^0 \to b\bar b$$ decays was obtained by requiring the presence of an electron or muon with high momentum and high momentum component transverse to the associated hadronic jet. After accounting for backgrounds and acceptances, a value of $$\frac{{\Gamma ({\rm Z}^0 \to b\bar b)}}{{\Gamma ({\rm Z}^0 \to hadrons)}} = 0.220 \pm 0.002 \pm 0.0006 \pm 0.011$$ was obtained. The first two errors reflect the data statistics and the systematic uncertainties arising from detector modelling uncertainties, respectively. The third error includes systematic effects fromb andc fragmentation and decay uncertainties.
Published: 1993

11. A measurement ofΓ (Z 0→b $$\Gamma ({\rm Z}^0 \to b\bar b)$$ /Γ(Z 0→hadrons) using an impact parameter technique

Author: Sachio Komamiya, E. Ros, A. T. Watson, A. Astbury, A. Skillman, U. Müller, T. P. Kokott, A. J. Martin, A. Luig, G. A. Snow, C. P. Ward, A. Gaidot, D. L. Rees, P. E.L. Clarke, I. J. Bloodworth, D. A. Hinshaw, James Pinfold, M. Kuwano, T. Wlodek, M. Sproston, J. Steuerer, D. G. Fong, Randall Sobie, G. D. Lafferty, J. Gascon, H. von der Schmitt, H. Przysiezniak, M. Fierro, P. Routenburg, N. Tesch, A. Dieckmann, M. Settles, T. W. Pritchard, F. Lamarche, R. J. Hemingway, C. K. Hargrove, G. Beaudoin, T. Behnke, Silvia Arcelli, P. Jovanovic, M. Foucher, T. Hilse, J. Mildenberger, Harold Nguyen, H. Takeda, F. G. Oakham, J. W. Gary, O. Runolfsson, F. S. Merritt, Austin Ball, Marcello Mannelli, J. E. Duboscq, D. Menszner, R. Yaari, Tohru Takeshita, Shlomo Dado, G. W. Wilson, Alessandro Montanari, D. Karlen, C. Beeston, C. Burgard, J. Hart, Claudio Grandi, S. Bethke, Marco Cuffiani, J. D. Gillies, M. W. Redmond, Otmar Biebel, Andris Skuja, R. J. Barlow, D. J. Miller, X. C. Lou, P. Igo-Kemenes, Georges Azuelos, G. Duckeck, R. Ströhmer, J. M. Lorah, M. J. Pearce, Horst Breuker, G. E. Richards, M. Yurko, Tetsuro Mashimo, P. W. Jeffreys, H. Jeremie, C. M. Hawkes, M. Cooper, J. F. Kral, U. Maur, K. W. Bell, D. G. Charlton, D. L. Wagner, G. T. Zorn, Giora Mikenberg, Daniel Lellouch, John Allison, W. Mohr, S. L. Chu, Gunter Wolf, Gregor Herten, Takehiko Mori, Max Weber, C. Wahl, J. C. Hill, Misao Sasaki, C. Jui, H. M. Bosch, Wolfram Dietrich Zeuner, J. M. Roney, P. Bright-Thomas, B. Wilkens, Matthias Schröder, E. do Couto e Silva, H. Mes, W. Gorn, P. A. Elcombe, I. P. Duerdoth, D. Axen, A. Jawahery, M. A. Thomson, R. G. Kellogg, M. Morii, H. Deng, R. Humbert, H. Lafoux, B. C. Shen, D. S. Koetke, Madjid Boutemeur, Peter Sherwood, J. A. McKenna, John Hobbs, Peter R Hobson, J. E. Pilcher, N. Paz-Jaoshvili, A. K. Honma, W. G. Scott, R. W. Springer, Alexander Wagner, Stefano Marcellini, James Letts, J. Hagemann, J. Ludwig, P. Scharff-Hansen, B. Fabbro, P. G. Estabrooks, R. K. Keeler, B. Panzer-Steindel, K. Runge, P. Bock, A. D. Schaile, R. Kowalewski, J. Becker, M. Hauschild, C. Markus, P. Paschievici, P. M. Watkins, M. J. Losty, Paul Kyberd, F. K. Loebinger, Gideon Bella, V. H. Winterer, A. M. Smith, G. J. VanDalen, Ehud Duchovni, S. Wotton, H. J. Burckhart, G. Vasseur, Jacqueline Batley, B. Lorazo, Norbert Wermes, P. Mättig, Sherry Towers, T. Kawamoto, R.J. Akers, R. Lahmann, D. C. Imrie, A. Rollnik, R. Giacomelli, O. Schaile, R. Bartoldus, J. Goldberg, S. Orito, M. Rosvick, B. Nellen, R. Mir, P. Leblanc, F. Odorici, H. G. Evans, M. J. Goodrick, I. Cohen, H. O. Ogren, Christoph Geich-Gimbel, M. Jimack, M. J. Oreglia, A. Yeaman, N. K. Watson, Erez Etzion, Stefan Kluth, Shlomit Tarem, J. R. Carter, S. Rossberg, C. J. Oram, G. N. Patrick, R. P. Middleton, J. Kroll, F. X. Gentit, J. E. Conboy, A. Pouladdej, H. Ihssen, S. W. O'Neale, S. W. Gensler, G. P. Siroli, K. J. Anderson, S. J. Hillier, Christoph Schwick, T. Kobayashi, C. J. Virtue, P. Poffenberger, Kiyotomo Kawagoe, W. R. Gibson, C. Y. Chang, M. F. Turner, A. Beck, E. Heflin, R. M. Brown, Lorne Levinson, P. Weber, B. W. Kennedy, E. Torrente-Lujan, D. E. Plane, P. Bentkowski, G. M. Dallavalle, D. J.P. Dumas, Gideon Alexander, Paolo Capiluppi, P. M. Hattersley, P. F. Harrison, P. D. Acton, Stephen Lloyd, M. Tecchio, T. J. Smith, K. Stephens, J. R. McNutt, V. Gibson, G. Quast, John Baines, D. R. Ward, G. Transtromer, A. M. Rossi, J. C. Clayton, T. Tsukamoto, S. Levegrün, H. M. Fischer, A. Michelini, A. C. Janissen, D. R. Rust, S. A. Robins, A. M. Lee, S. Barnett, C. Sbarra, D. Hochman, Michael Dittmar, G. Yekutieli, A. A. Carter, Roger Jones, J. Banks, N. J. Tresilian, R. D. Heuer, R. Van Kooten, Fabrizio Fabbri, D. Van den plas, N. I. Geddes, D. Pitman, M. H. Lehto, B. Boden, B. Poli, T. G. Shears, D. M. Gingrich, P. Berlich, L. Köpke, J. P. Martin, T. J. McMahon, M. Hansroul, S. De Jong, J. Schwiening, R. K. Carnegie, C. H. Shepherd-Themistocleous, J. A. Wilson, R. J. Homer, W. Schappert, Margret Fincke-Keeler, J. G. Layter, R. E. Hughes-Jones, J. von Krogh, P. Pfister, G. G. Hanson, G. Giacomelli, Dave Robinson, P. Schenk, M. S. Dixit, Frans Meijers, L. A. del Pozo, C. Moisan, G. A. Beck, Achim Stahl, P. Teixeira-Dias, B. Schmitt, P. S. Wells, Terry Richard Wyatt, M. Coupland, F. C. Grant, M. A. Whalley, A. Buijs, D. M. Strom, C. Stegmann, M. Jones, Claude Leroy, and J. P. Pansart
Subjects: Quark, Physics, Partial width, Physics and Astronomy (miscellaneous), Astrophysics::High Energy Astrophysical Phenomena, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Analytical chemistry, Elementary particle, Standard Model, High Energy Physics::Experiment, Impact parameter, Engineering (miscellaneous), Bar (unit)
Abstract: The fractional partial width of theZ0 tob quarks,$\Gamma _{b\bar b} /\Gamma _{had} $, has been measured by OPAL using an impact parameter technique. The method has been developed using 130 000 hadronic events collected by OPAL in 1990. We find: $$\frac{{\Gamma _{b\bar b} }}{{\Gamma _{had} }} = 0.222 \pm 0.007(stat) \pm 0.008(sys).$$ The measurement assumes the relative rates of theZ0 touds andc quarks given by the Standard Model. Varying the charm fraction from the Standard Model value of$\Gamma _{c\bar c} /\Gamma _{had} = 0.171$ changes the result by an additional$\Delta \Gamma _{b\bar b} /\Gamma _{b\bar b} = - 0.135 \times \Delta \Gamma _{c\bar c} /\Gamma _{c\bar c} $.
Published: 1993

12. A measurement of the forward-backward asymmetry of $$e^ + e^ - \to c\bar c$$ and $$e^ + e^ - \to b\bar b$$ at centre of mass energies on and near theZ 0 peak usingD *± mesons

Author: T. J. Smith, K. Stephens, J. R. McNutt, G. Quast, John Baines, D. R. Ward, G. Transtromer, S. Barnett, D. Hochman, G. J. VanDalen, M. Rosvkck, J. C. Clayton, M. Yurko, Silvia Arcelli, S. A. Robins, R. Lahmann, F. S. Merritt, P. W. Jeffreys, Margret Fincke-Keeler, W. R. Gibson, D. C. Imrie, Matthias Schröder, Gunter Wolf, T. Kobayashi, H. Lafoux, N. Paz-Jaoshvili, P. Igo-Kemenes, D. A. Hinshaw, Gregor Herten, C. Wahl, B. Wilkens, P. E.L. Clarke, A. Beck, E. Heflin, G. P. Siroli, E. Lefebvre, J. P. Martin, S. L. Chu, J. King, Christoph Schwick, V. H. Winterer, S. Wotton, C. M. Hawkes, M. Cooper, Daniel Lellouch, Otmar Biebel, G. E. Richards, D. G. Charlton, D. L. Wagner, R. M. Brown, P. Bright-Thomas, H. Jeremie, Lorne Levinson, R. E. Hughes-Jones, U. Maur, A. Skillman, J. E. Pilcher, H. Deng, R. Humbert, J. Lauber, F. Odorici, S. De Jong, M. Morii, P. Pfister, Takehiko Mori, A. Gaidot, Georges Azuelos, Peter R Hobson, V. Gibson, R.J. Akers, B. Fabbro, B. W. Kennedy, Gilles Beaudoin, E. Torrente-Lujan, R. Bartoldus, T. Wlodek, M. Sproston, M. Sasaki, H. Takeda, E. do Couto e Silva, B. Boden, H. O. Ogren, B. Panzer-Steindel, R. G. Kellogg, J. Goldberg, P. Routenburg, J. Schneps, B. Poli, Kiyotomo Kawagoe, Norbert Wermes, J. F. Kral, Christoph Geich-Gimbel, Sherry Towers, T. Kawamoto, M. A. Thomson, G. A. Snow, C. P. Ward, F. G. Oakham, J. A. McKenna, D. S. Koetke, N. Tesch, A. Dieckmann, John Hobbs, K. W. Bell, B. Nellen, D. L. Rees, D. E. Plane, D. Axen, A. Jawahery, P. A. Elcombe, Max Weber, P. Leblanc, Stefano Marcellini, S. Orito, M. J. Pearce, Horst Breuker, J. Hart, P. Bentkowski, G. M. Dallavalle, Gideon Bella, Peter Sherwood, James Letts, J. C. Hill, B. C. Shen, R. Mir, G. D. Lafferty, J. Kroll, C. Moisan, J. Becker, R. W. Springer, Alexander Wagner, S. W. O'Neale, G. A. Beck, J. D. Gillies, H. J. Burckhart, H. Mes, I. P. Duerdoth, T. Takeeshita, J. Hagemann, S. L. Lloyd, F. X. Gentit, Jacqueline Batley, Madjid Boutemeur, Achim Stahl, A. Yeaman, H. G. Evans, A. K. Honma, W. G. Scott, J. Ludwig, K. Runge, P. Bock, J. Mildenberger, Harold Nguyen, P. Mättig, M. J. Goodrick, I. Cohen, D. J.P. Dumas, J. E. Conboy, A. Astbury, P. Teixeira-Dias, F. Scharf, J. Steuerer, J. W. Gary, Shlomo Dado, P. Weber, N. K. Watson, I. J. Bloodworth, C. Jui, P. F. Harrison, U. Müller, N. I. Geddes, A. J. Martin, Sachio Komamiya, D. J. Miller, M. Settles, G. G. Hanson, P. G. Estabrooks, G. Mikenberg, J. Allison, G. Duckeck, R. Ströhmer, M. Tecchio, M. J. Oreglia, M. W. Redmond, X. C. Lou, R. K. Keeler, E. Ros, M. Foucher, M. J. Losty, G. Giacomelli, B. Schmitt, G. T. Zorn, A. D. Schaile, T. Behnke, Erez Etzion, K. J. Anderson, G. W. Wilson, P. Schenk, Paul Kyberd, J. M. Roney, D. Karlen, R. Kowalewski, H. M. Bosch, C. K. Hargrove, Wolfram Dietrich Zeuner, T. P. Kokott, A. Luig, R. J. Barlow, C. Burgard, F. K. Loebinger, M. Hauschild, P. M. Watkins, R. Yaari, G. N. Patrick, Stefan Kluth, S. Bethke, Marco Cuffiani, M. S. Dixit, R. J. Hemingway, Shlomit Tarem, A. M. Rossi, Frans Meijers, J. M. Lorah, Gideon Alexander, H. Przysiezniak, Paolo Capiluppi, C. Markus, T. Tsukamoto, P. Paschievici, C. Y. Chang, H. M. Fischer, S. Rossberg, C. J. Oram, M. F. Turner, A. Rollnik, P. Poffenberger, R. Giacomelli, M. Fierro, A. Michelini, M. Hansroul, Ehud Duchovni, A. C. Janissen, R. P. Middleton, P. Jovanovic, J. G. Layter, M. Jimack, Austin Ball, H. Ihssen, D. Menszner, S. W. Gensler, Alessandro Montanari, S. J. Hillier, T. Hilse, C. H. Shepherd-Themistocleous, T. W. Pritchard, O. Runolfsson, J. R. Carter, R. J. Homer, James Pinfold, D. G. Fong, C. Beeston, Claudio Grandi, P. S. Wells, J. Gascon, H. von der Schmitt, Terry Richard Wyatt, A. T. Watson, M. Coupland, P. M. Hattersley, Marcello Mannelli, J. E. Duboscq, R. W.L. Jones, M. Jones, R. J. Sobie, P. Scharff-Hansen, Claude Leroy, A. M. Smith, J. P. Pansart, G. Vasseur, B. Lorazo, F. C. Grant, M. A. Whalley, Andris Skuja, A. Buijs, D. M. Strom, C. Stegmann, Tetsuro Mashimo, W. Gorn, J. von Krogh, Dave Robinson, L. A. del Pozo, C. Sbarra, Michael Dittmar, G. Yekutieli, A. A. Carter, R. Van Kooten, M. G. Rison, T. J. McMahon, W. Mohr, J. Schwiening, R. K. Carnegie, J. A. Wilson, W. Schappert, D. R. Rust, A. M. Lee, O. Schaile, J. Banks, N. J. Tresilian, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, D. Pitman, M. H. Lehto, T. G. Shears, D. M. Gingrich, and P. Berlich
Subjects: Physics, Quark, Particle physics, Physics and Astronomy (miscellaneous), Meson, media_common.quotation_subject, Electron–positron annihilation, Elementary particle, Asymmetry, Standard Model, Nuclear physics, Charm (quantum number), Engineering (miscellaneous), media_common, Bar (unit)
Abstract: A measurement is presented of the forwardbackward asymmetry of the processes$e^ + e^ + \to c\bar c$ and$e^ + e^ + \to b\bar b$ at centre of mass energies near 91 GeV. Decays of theZ0 into charm and bottom quarks are identified using 6507 chargedD* mesons, reconstructed in the decaysD*±→D0π±→(K∓π±)π±,D*±→D0π±→(K∓π±π0)π± andD*±→D0π±→(K∓π±π∓π±)π±. Thec quark asymmetry on theZ0 peak is measured to be $$A_{FB}^c = 0.052 \pm 0.028(stat.) \pm 0.012(sys.).$$ The energy dependence of the asymmetry has been investigated at energies close to theZ0 peak. Consistency with the predictions of the Standard Model is found.
Published: 1993

13. ψproduction inp¯Nandπ−Ninteractions at 125 GeV/cand a determination of the gluon structure functions of thep¯and theπ−

Author: Spyros Tzamarias, W. Schappert, S. Katsanevas, J. Enagonio, Dg Stairs, S. Conetti, D. Nitz, Christine Kourkoumelis, Zhang Nai-Jian, H. Areti, A. Markou, R. L. Wagner, R. Kephart, He Mao, L. K. Resvanis, Wannian Yang, D. G. Ryan, P. Kraushaar, D. Judd, R. P. Thun, P. K. Malhotra, C. Hojvat, Bradley Cox, Timothy A. Ryan, M. Binkley, G. Voulgaris, P.O. Mazur, D. E. Wagoner, F. Turkot, Carl W. Akerlof, and P. Lebrun
Subjects: Physics, Particle physics, Crystallography, Angular distribution, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Structure function, Transverse momentum, Pi, Calculation methods, MathematicsofComputing_DISCRETEMATHEMATICS, Gluon, Bar (unit)
Abstract: We have measured the cross section for production of [psi] and [psi][prime] in [ital [bar p]] and [pi][sup [minus]] interactions with Be, Cu, and W targets in experiment E537 at Fermilab. The measurements were performed at 125 GeV/[ital c] using a forward dimuon spectrometer in a closed geometry configuration. The gluon structure functions of the [ital [bar p]] and [pi][sup [minus]] have been extracted from the measured [ital d][sigma]/[ital dx][sub [ital F]] spectra of the produced [psi]'s. From the [ital [bar p]]W data we obtain, for [ital [bar p]], [ital xG]([ital x])=(2.15[plus minus]0.7)[1[minus][ital x]][sup (6.83[plus minus]0.5)] [1+(5.85[plus minus]0.95)[ital x]]. In the [pi][sup [minus]] case, we obtain, from the W and the Be data separately, [ital xG]([ital x])=(1.49[plus minus]0.03)[1[minus][ital x]][sup (1.98[plus minus]0.06)] (for [pi][sup [minus]]W), [ital xG]([ital x])=(1.10[plus minus]0.10)[1[minus][ital x]][sup (1.20[plus minus]0.20)] (for [pi][sup [minus]]Be).
Published: 1993

14. A test of the flavour independence of the strong interaction for five flavours

Author: James Pinfold, D. G. Fong, J. Gascon, H. von der Schmitt, J. W. Gary, Marcello Mannelli, J. E. Duboscq, Andris Skuja, Tetsuro Mashimo, W. Gorn, P. Scharff-Hansen, A. M. Smith, G. Vasseur, B. Lorazo, P. A. Elcombe, G. Beaudoin, Tohru Takeshita, Gregor Herten, Gideon Bella, J. Becker, Sachio Komamiya, Otmar Biebel, C. Wahl, P. M. Hattersley, B. Wilkens, H. J. Burckhart, Georges Azuelos, P. Igo-Kemenes, F. C. Grant, D. G. Charlton, D. L. Wagner, M. A. Whalley, F. Scharf, Jacqueline Batley, K. Stephens, E. Ros, A. T. Watson, Shlomo Dado, Madjid Boutemeur, J. F. Kral, J. R. McNutt, F. S. Merritt, H. Mes, K. W. Bell, I. P. Duerdoth, Max Weber, J. E. Pilcher, R. Lahmann, J. C. Hill, D. C. Imrie, H. Deng, R. Humbert, X. C. Lou, H. Jeremie, Misao Sasaki, B. C. Shen, M. Hansroul, C. Y. Chang, N. I. Geddes, R.J. Akers, Giora Mikenberg, G. P. Siroli, J. King, A. K. Honma, R. E. Hughes-Jones, A. Buijs, U. Maur, D. M. Strom, Christoph Schwick, W. R. Gibson, P. G. Estabrooks, W. G. Scott, B. Boden, M. F. Turner, O. Schaile, B. Poli, T. P. Kokott, C. Stegmann, A. Luig, J. M. Lorah, R. K. Keeler, V. Gibson, J. A. McKenna, Norbert Wermes, A. Beck, Sherry Towers, T. Kawamoto, G. Quast, R. Kowalewski, E. Heflin, R. M. Brown, Kiyotomo Kawagoe, E. do Couto e Silva, W. Mohr, Lorne Levinson, John Baines, M. J. Losty, R. Bartoldus, P. M. Watkins, G. A. Snow, C. P. Ward, D. L. Rees, C. H. Shepherd-Themistocleous, R. J. Homer, B. W. Kennedy, E. Torrente-Lujan, A. Skillman, P. Weber, A. Gaidot, S. Orito, M. Rosvick, R. Mir, H. Przysiezniak, H. O. Ogren, Christoph Geich-Gimbel, M. Hauschild, D. E. Plane, Margret Fincke-Keeler, M. Fierro, D. R. Ward, G. Transtromer, T. Wlodek, G. T. Zorn, M. Sproston, C. Markus, P. Paschievici, P. Bentkowski, G. M. Dallavalle, Silvia Arcelli, Matthias Schröder, G. J. VanDDalen, B. Fabbro, N. Tesch, A. Dieckmann, E. Lefebvre, P. Poffenberger, J. Banks, M. J. Oreglia, J. Kroll, J. C. Clayton, B. Panzer-Steindel, A. M. Rossi, P. Pfister, F. Odorici, T. Hilse, F. X. Gentit, H. Lafoux, D. J.P. Dumas, T. Tsukamoto, H. M. Fischer, N. Paz-Jaoshvili, N. J. Tresilian, O. Runolfsson, P. S. Wells, A. Michelini, A. C. Janissen, M. Mori, J. R. Carter, G. N. Patrick, Terry Richard Wyatt, Peter R Hobson, C. Beeston, R. D. Heuer, M. Coupland, C. Moisan, Claudio Grandi, Gideon Alexander, P. Routenburg, M. Yurko, G. A. Beck, Fabrizio Fabbri, J. M. Roney, A. Astbury, S. A. Robins, P. W. Jeffreys, Paolo Capiluppi, Achim Stahl, P. Teixeira-Dias, D. Van den plas, U. Müller, M. Jones, A. J. Martin, B. Schmitt, D. Pitman, P. Bright-Thomas, G. Giacomelli, J. Hart, S. W. O'Neale, K. J. Anderson, M. H. Lehto, G. Yukutieli, J. D. Gillies, P. Ma:attig, M. A. Thomson, P. Schenk, A. Yeaman, S. Barnett, J. von Krogh, T. G. Shears, Claude Leroy, N. K. Watson, J. Steuerer, R. J. Barlow, D. Hochman, J. P. Pansart, C. K. Hargrove, M. S. Dixit, D. J. Miller, Frans Meijers, D. M. Gingrich, Dave Robinson, P. F. Harrison, P. E.L. Clarke, M. J. Pearce, Horst Breuker, Stephen Lloyd, J. P. Martin, L. A. del Pozo, C. Sbarra, P. Berlich, J. Lauber, R. Yaari, M. Tecchio, S. Bethke, S. De Jong, Marco Cuffiani, H. Takeda, F. G. Oakham, Michael Dittmar, D. R. Rust, S. L. Chu, Ehud Duchovni, R. J. Hemingway, Erez Etzion, M. Jimack, P. Jovanovic, H. Ihssen, Austin Ball, D. Menszner, A. M. Lee, Stefan Kluth, Shlomit Tarem, J. G. Layter, John Hobbs, Alessandro Montanari, J. E. Conboy, A. A. Carter, S. W. Gensler, S. J. Hillier, Roger Jones, T. Kobayashi, D. Axen, A. Jawahery, R. Van Kooten, S. Rossberg, C. J. Oram, Peter Sherwood, R. W. Springer, Alexander Wagner, M. G. Rison, J. Hagemann, R. P. Middleton, J. Ludwig, K. Runge, P. Bock, Gunter Wolf, T. J. McMahon, G. Duckeck, R. Ströhmer, J. Schwiening, R. K. Carnegie, H. M. Bosch, Wolfram Dietrich Zeuner, J. A. Wilson, S. Wotton, W. Schappert, D. A. Hinshaw, J. Goldberg, T. Behnke, B. Nellen, P. Leblanc, H. G. Evans, M. J. Goodrick, I. Cohen, Randall Sobie, G. D. Lafferty, T. W. Pritchard, A. D. Schaile, V. H. Winterer, G. E. Richard, C. Jui, C. M. Hawkes, M. Cooper, Daniel Lellouch, I. J. Bloodworth, M. Settles, M. Foucher, G. W. Wilson, D. Karlen, C. Burgard, J. Mildenberger, Harold Nguyen, T. J. Smith, Gordon H. Hanson, M. W. Redmond, John Allison, R. G. Kellogg, D. S. Koetke, Stefano Marcellini, James Letts, Paul Kyberd, F. K. Loebinger, A. Rollnik, and R. Giacomelli
Subjects: Quark, Physics, Strange quark, Particle physics, Muon, Annihilation, Physics and Astronomy (miscellaneous), Meson, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Strong interaction, Charge (physics), High Energy Physics::Experiment, Production (computer science), Engineering (miscellaneous), Particle Physics - Experiment
Abstract: We report on a measurement of the ratio of the strong coupling constants$\alpha _s (M_{Z^0 } )$ for various data samples with different quark flavour compositions obtained frome+e− annihilation at LEP. We select events with muons, electrons, andD*± mesons from charm and bottom decays, events with highly energeticKs0 mesons originating predominantly from strange quarks, and events with highly energetic stable charged particles from a combination of up, down and strange quarks. From the jet production rates in these events we obtain from these samples the relative value of αs for the individual quark flavours as $$\begin{gathered} \frac{{\alpha _s^b }}{{\alpha _s^{udsc} }} = 1.017 \pm 0.036,\frac{{\alpha _s^c }}{{\alpha _s^{udsb} }} = 0.918 \pm 0.115, \hfill \\ \frac{{\alpha _s^s }}{{\alpha _s^{udcb} }} = 1.158 \pm 0.164,\frac{{\alpha _s^{uds} }}{{\alpha _s^{cb} }} = 1.038 \pm 0.221, \hfill \\ \end{gathered}$$ with quadratically combined statistical and systematic errors. We also compare the αs values for quarks of diffrent weak isospin, charge and generation. No evidence for a dependence of αs on any of these quark properties is observed. Finally, combining all samples and determining the αsf/αsincl ratio for each flavour, we do not find any dependence of the strong coupling constant on flavour.
Published: 1993

15. Studies of strong and electroweak interactions using final state photon emission in hadronicZ 0 decays

Author: B. C. Shen, Gideon Bella, A. K. Honma, H. J. Burckhart, Jacqueline Batley, W. G. Scott, V. Gibson, G. Quast, Tara Shears, John Baines, R. Kowalewski, Horst Breuker, M. J. Losty, R. Lahmann, D. C. Imrie, T. J. Smith, M. Morii, D. R. Ward, G. Transtromer, Peter R Hobson, P. Mättig, H. O. Ogren, R. Mir, I. J. Bloodworth, P. S. Wells, James Pinfold, T. Mouthuy, C. Y. Chang, M. F. Turner, G. P. Siroli, P. A. Elcombe, Christoph Schwick, Terry Richard Wyatt, S. Barnett, P. Taras, J. Mildenberger, M. Settles, M. Coupland, Christoph Geich-Gimbel, D. G. Fong, Sachio Komamiya, Harold Nguyen, G. T. Zorn, G. Beaudoin, D. Hochman, N. J. Thackray, E. Ros, J. Gascon, H. von der Schmitt, A. Astbury, Mitsuaki Nozaki, M. J. Oreglia, M. Foucher, O. Ganel, F. C. Grant, M. A. Whalley, A. J. Martin, J. Becker, J. Goldberg, A. M. Rossi, C. K. Hargrove, T. P. Kokott, Carla Sbarra, F. Odorici, N. Paz-Jaoshvili, M. Hauschild, Shlomo Dado, J. W. Gary, T. Tsukamoto, B. Nellen, P. Leblanc, S. Levegrün, G. J. VanDalen, G. W. Wilson, J. C. Clayton, D. Karlen, C. Burgard, Marcello Mannelli, J. E. Duboscq, A. Buijs, D. M. Strom, X. C. Lou, C. Markus, P. Paschievici, J. R. Carter, G. N. Patrick, Tohru Takeshita, H. G. Evans, P. Igo-Kemenes, G. Maringer, M. J. Goodrick, I. Cohen, Giora Mikenberg, D. Axen, A. Jawahery, H. Jeremie, Kiyotomo Kawagoe, A. Simon, Otmar Biebel, Georges Azuelos, C. M. Hawkes, P. E.L. Clarke, J. Steuerer, Andris Skuja, M. Cooper, P. Singh, G. Tysarczyk-Niemeyer, R. E. Hughes-Jones, U. Maur, Erez Etzion, G. E. Richards, Daniel Lellouch, D. L. Wagner, C. Jui, Tetsuro Mashimo, Stefan Kluth, Shlomit Tarem, Peter Sherwood, H. Deng, R. Humbert, J. F. Kral, K. W. Bell, P. G. Estabrooks, Max Weber, S. W. O'Neale, Paul Kyberd, F. K. Loebinger, N. I. Geddes, R. W. L. Jones, K. J. Anderson, R. W. Springer, Alexander Wagner, Takehiko Mori, H. Mes, S. Rossberg, C. J. Oram, J. C. Hill, Misao Sasaki, M. Hansroul, J. Hagemann, E. do Couto e Silva, I. P. Duerdoth, M. W. Redmond, W. Gorn, Richard Keeler, J. Ludwig, K. Runge, R. P. Middleton, F. G. Oakham, P. M. Watkins, B. Boden, P. Weber, A. Yeaman, B. Poli, Norbert Wermes, J. Kroll, P. Bock, B. Panzer-Steindel, G. A. Snow, C. P. Ward, A. Rollnik, R. Giacomelli, M. Jobes, U. Binder, J. M. Lorah, P. Scharff-Hansen, C. H. Shepherd-Themistocleous, D. L. Rees, T. Kawamoto, J. Hart, O. Schaile, F. X. Gentit, P. Poffenberger, S. Wotton, R. J. Homer, H. M. Fischer, S. Orito, M. Rosvick, J. D. Gillies, A. Michelini, J. E. Conboy, W. Mohr, J. Banks, Claude Leroy, J. P. Pansart, Silvia Arcelli, A. C. Janissen, M. Jimack, John Allison, R. Yaari, S. Bethke, Marco Cuffiani, A. D. Schaile, N. J. Tresilian, G. Duckeck, R. Ströhmer, N. K. Watson, C. Moisan, J. P. Walker, M. A. Thomson, A. M. Smith, G. A. Beck, D. G. Charton, R. J. Barlow, G. Vasseur, B. Lorazo, R. D. Heuer, P. Teixeira-Dias, Fabrizio Fabbri, A. Gaidot, R. G. Kellogg, D. J. Miller, A. Pouladdej, D. Van den plas, M. Kuwano, T. Wlodek, M. Sproston, D. S. Koetke, Stefano Marcellini, P. M. Hattersley, D. R. Rust, B. Schmitt, H. M. Bosch, S. L. Chu, J. M. Roney, P. Routenburg, James Letts, N. Tesch, A. Dieckmann, Wolfram Dietrich Zeuner, Margret Fincke-Keeler, F. Lamarche, V. H. Winterer, F. S. Merritt, D. A. Hinshaw, R. J. Hemingway, D. Pitman, M. H. Lehto, T. Behnke, P. Jovanovic, J. A. McKenna, Austin Ball, D. Menszner, R. F. McGowan, G. A. Bahn, John Hobbs, P. Berlich, Alessandro Montanari, L. Köpke, W. J. Collins, C. Wahl, Randall Sobie, G. D. Lafferty, J. E. Pilcher, T. W. Pritchard, S. Schreiber, T. J. McMahon, J. Schwiening, R. K. Carnegie, J. A. Wilson, W. Schappert, J. von Krogh, Dave Robinson, L. A. del Pozo, Michael Dittmar, G. Yekutieli, A. A. Carter, R. Van Kooten, W. R. Gibson, A. Beck, E. Heflin, R. M. Brown, Lorne Levinson, B. W. Kennedy, E. Torrente-Lujan, M. Yurko, P. W. Jeffreys, A. M. Lee, D. E. Plane, P. Bentkowski, P. Bright-Thomas, G. M. Dallavalle, Alan Watson, D. J.P. Dumas, H. Przysiezniak, M. Fierro, P. F. Harrison, T. Hilse, P. D. Acton, Stephen Lloyd, O. Runolfsson, M. Tecchio, Phillip Allport, Gideon Alexander, Paolo Capiluppi, Claudio Grandi, Ehud Duchovni, R. Shypit, H. Ihssen, S. W. Gensler, S. J. Hillier, T. Kobayashi, C. J. Virtue, P. Pfister, J. G. Layter, J. P. Martin, S. De Jong, G. G. Hanson, G. Giacomelli, P. Schenk, M. S. Dixit, Frans Meijers, K. Stephens, and J. R. McNutt
Subjects: Quantum chromodynamics, Physics, Quark, Particle physics, Photon, Physics and Astronomy (miscellaneous), Hadron, Electroweak interaction, Type (model theory), Jet (particle physics), Standard Model, Nuclear physics, High Energy Physics::Experiment, Engineering (miscellaneous), Particle Physics - Experiment
Abstract: The cross section and jet rates ofZ0 decays into photons and quarks are compared with matrix element Monte Carlos ofO(ααs). Good agreement is found between data and theoretical predictions. From the ratio of events with three jets plus a photon to those with two jets plus a photon, αs in first order is determined to be 0.176±0.010. Combining the cross section of final state photon events with the LEP average hadronic partial decay width of theZ0, the widths of theZ0 into up and down type quarks can be calculated. The results $$\begin{gathered} \Gamma _{u - type} = 242 \pm 46MeV; \hfill \\ \Gamma _{d - type} = 419 \pm 30MeV \hfill \\ \end{gathered} $$ are in good agreement with the standard model expectation. A comparison of the measured cross section as a function ofycut with predictions of QCD shower models shows that, at the current level of accuracy ARIADNE and, to a lesser extent, HERWIG and JETSET can reproduce the measurement.
Published: 1993

16. Search for massive, unstable photinos that violate R parity

Author: R. Bartoldus, C. Y. Chang, M. F. Turner, H. O. Ogren, S. W. O'Neale, K. J. Anderson, B. C. Shen, Christoph Geich-Gimbel, M. Yurko, G. Beaudoin, P. Poffenberger, James Pinfold, C. Moisan, G. A. Beck, H. Mes, I. P. Duerdoth, Erez Etzion, D. Axen, A. Jawahery, Silvia Arcelli, D. G. Fong, J. Gascon, H. von der Schmitt, A. K. Honma, P. W. Jeffreys, Stefan Kluth, M. Jones, Richard Keeler, Shlomit Tarem, Gideon Bella, W. G. Scott, G. Giacomelli, G. T. Zorn, Shlomo Dado, S. L. Chu, R. Kowalewski, Otmar Biebel, Peter Sherwood, G. E. Richards, J. Hart, T. J. Smith, Achim Stahl, P. Teixeira-Dias, R. W. Springer, Alexander Wagner, J. D. Gillies, R.J. Akers, B. Schmitt, J. W. Gary, H. J. Burckhart, Jacqueline Batley, J. C. Clayton, R. J. Barlow, J. Kroll, P. Schenk, O. Schaile, J. Hagemann, J. Ludwig, K. Runge, P. Bock, P. Igo-Kemenes, A. M. Rossi, T. Tsukamoto, S. Levegrün, Marcello Mannelli, J. E. Duboscq, P. Bright-Thomas, H. Jeremie, D. J. Miller, S. Rossberg, C. J. Oram, M. J. Losty, F. X. Gentit, X. C. Lou, Giora Mikenberg, C. Jui, J. E. Conboy, D. G. Charlton, D. L. Wagner, M. S. Dixit, Frans Meijers, P. Mättig, Claude Leroy, J. P. Pansart, U. Maur, I. J. Bloodworth, R. P. Middleton, H. Deng, R. Humbert, N. I. Geddes, A. Pouladdej, F. Odorici, R. Lahmann, J. G. Layter, M. Hansroul, P. Scharff-Hansen, D. A. Hinshaw, D. C. Imrie, J. Goldberg, B. Boden, B. Poli, Gregor Herten, J. M. Roney, M. Settles, Norbert Wermes, A. D. Schaile, Sherry Towers, T. Kawamoto, B. Nellen, F. S. Merritt, C. Wahl, M. Morii, E. do Couto e Silva, M. Foucher, C. H. Shepherd-Themistocleous, Tohru Takeshita, H. M. Fischer, G. A. Snow, B. Wilkens, C. P. Ward, A. M. Smith, H. Takeda, P. Leblanc, John Hobbs, Peter R Hobson, S. Orito, M. Rosvick, R. J. Homer, A. Michelini, A. C. Janissen, D. L. Rees, F. G. Oakham, Madjid Boutemeur, G. W. Wilson, V. H. Winterer, T. Behnke, R. Mir, G. P. Siroli, Georges Azuelos, G. Vasseur, Margret Fincke-Keeler, B. Lorazo, J. E. Pilcher, D. Karlen, C. Burgard, H. Przysiezniak, Andris Skuja, Christoph Schwick, F. Lamarche, P. G. Estabrooks, C. M. Hawkes, M. Cooper, Daniel Lellouch, S. A. Robins, M. Fierro, J. F. Kral, K. W. Bell, J. P. Martin, R. J. Hemingway, J. A. McKenna, M. Hauschild, Tetsuro Mashimo, Takehiko Mori, P. Pfister, P. E.L. Clarke, P. S. Wells, P. M. Watkins, H. G. Evans, S. Barnett, M. J. Oreglia, J. Steuerer, S. De Jong, Max Weber, P. Jovanovic, Austin Ball, M. J. Goodrick, D. Menszner, T. Hilse, Randall Sobie, I. Cohen, G. D. Lafferty, Terry Richard Wyatt, O. Runolfsson, W. Gorn, B. Fabbro, A. Yeaman, B. Panzer-Steindel, J. C. Hill, N. K. Watson, Misao Sasaki, Alessandro Montanari, J. R. Carter, T. W. Pritchard, G. N. Patrick, C. Beeston, M. Coupland, Claudio Grandi, D. Hochman, Sachio Komamiya, Gideon Alexander, Paolo Capiluppi, E. Ros, Gunter Wolf, F. C. Grant, M. A. Whalley, P. M. Hattersley, T. P. Kokott, A. Luig, R. Yaari, S. Bethke, Marco Cuffiani, A. Buijs, D. M. Strom, C. Stegmann, K. Stephens, Kiyotomo Kawagoe, P. F. Harrison, J. R. McNutt, P. D. Acton, Stephen Lloyd, M. Tecchio, Ehud Duchovni, S. Wotton, M. Jimack, P. Weber, H. Ihssen, S. W. Gensler, S. J. Hillier, T. Kobayashi, G. Duckeck, R. Ströhmer, C. J. Virtue, V. Gibson, G. Quast, John Baines, H. M. Bosch, Wolfram Dietrich Zeuner, D. R. Ward, G. Transtromer, A. Astbury, U. Müller, A. J. Martin, Paul Kyberd, F. K. Loebinger, A. Rollnik, R. Giacomelli, John Allison, R. G. Kellogg, D. S. Koetke, Stefano Marcellini, James Letts, J. Mildenberger, Harold Nguyen, Gordon H. Hanson, M. W. Redmond, C. K. Hargrove, Matthias Schröder, H. Lafoux, N. Paz-Jaoshvili, Tara Shears, M. J. Pearce, Horst Breuker, C. Markus, P. Paschievici, D. Pitman, M. H. Lehto, D. M. Gingrich, P. Berlich, L. Köpke, D. R. Rust, A. M. Lee, J. Banks, N. J. Tresilian, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, D. E. Plane, P. Bentkowski, G. M. Dallavalle, Alan Watson, D. J.P. Dumas, W. R. Gibson, A. Beck, E. Heflin, R. M. Brown, Lorne Levinson, B. W. Kennedy, E. Torrente-Lujan, C. Sbarra, Michael Dittmar, G. Yekutieli, A. A. Carter, Roger Jones, R. Van Kooten, R. E. Hughes-Jones, J. von Krogh, Dave Robinson, L. A. del Pozo, T. J. McMahon, J. Schwiening, R. K. Carnegie, J. A. Wilson, W. Schappert, A. Skillman, M. A. Thomson, A. Gaidot, M. Kuwano, T. Wlodek, M. Sproston, P. Routenburg, N. Tesch, A. Dieckmann, P. A. Elcombe, J. Becker, G. J. VanDalen, J. M. Lorah, and W. Mohr
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Magnetic moment, Solar neutrino, High Energy Physics::Phenomenology, Supersymmetry, Parameter space, lcsh:QC1-999, Nuclear physics, R-parity, High Energy Physics::Experiment, Neutrino, Photino, Particle Physics - Experiment, lcsh:Physics, Lepton
Abstract: A search for unstable, massive photinos pair produced in e + e − collisions has been performed using the OPAL detector at LEP. The data sample corresponds to an integrated luminosity of 21 pb −1 collected at center-of-mass energies near the Z 0 resonance. The unstable photino is assumed to decay into τ ± / gn l ( l = e or μ ) final states, thereby violating individual lepton numbers and R parity. This search is inspired by a particular model of supersymmetry which is of interest within the context of solar neutrino experiments because it allows for a large neutrino magnetic moment. The present search excludes a large portion of the parameter space allowed by the model.
Published: 1993

17. Measurement of the B0 and B+ lifetimes

Author: W. R. Gibson, A. Beck, E. Heflin, R. M. Brown, G. Transtromer, B. W. Kennedy, E. Torrente-Lujan, M. Fincke-Keeler, D. E. Plane, P. Bentkowski, Alan Watson, D. J.P. Dumas, Silvia Arcelli, Tara Shears, P. Igo-Kemenes, G. Maringer, R. Sobie, H. Jeremie, R. E. Hughes-Jones, U. Maur, P. Bright-Thomas, Horst Breuker, H. M. Fischer, E. do Couto e Silva, J. Pinfold, C. Burgard, F. C. Grant, P. E.L. Clarke, M. A. Whalley, A. Michelini, A. C. Janissen, O. Ganel, G. A. Snow, C. P. Ward, R. Yaari, H. O. Ogren, Christoph Geich-Gimbel, A. Simon, D. L. Rees, A. Buijs, M. Jobes, Otmar Biebel, G. E. Richards, U. Binder, D. G. Charlton, D. L. Wagner, P. G. Estabrooks, N. Paz-Jaoshvili, P. Scharff-Hansen, J. Kroll, G. Yekutieli, F. X. Gentit, H. Deng, R. Humbert, J. E. Conboy, P. M. Watkins, G. Beaudoin, D. R. Rust, A. Pouladdej, Paul Kyberd, F. K. Loebinger, B. C. Shen, C. Schwick, A. M. Smith, F. S. Merritt, J. Steuerer, D. Strom, G. Vasseur, B. Lorazo, Kiyotomo Kawagoe, A. Astbury, M. W. Redmond, W. G. Scott, Richard Keeler, Norbert Wermes, T. Kawamoto, G. M. Dallavale, N. I. Geddes, A. J. Martin, J. A. McKenna, Shlomo Dado, A. Rollnik, R. Giacomelli, F. G. Oakham, D. Hochman, C. Y. Chang, M. F. Turner, M. Morii, S. Bethke, P. Taras, Peter R Hobson, R. Kowalewski, B. Boden, Marco Cuffiani, Mitsuaki Nozaki, R. F. McGowan, Claude Leroy, D. G. Fong, J. P. Pansart, B. Poli, J. Gascon, J. Hart, S. Orito, P. Weber, S. Tarem, T. Behnke, Sachio Komamiya, E. Ros, X. C. Lou, H. von der Schmitt, M. J. Losty, M. Jimack, H. Ihssen, John Allison, G. Quast, C. K. Hargrove, S. L. Chu, J. R. McNutt, J. D. Gillies, Gideon Bella, P. Pfister, R. Mir, S. W. Gensler, T. P. Kokott, Carla Sbarra, T. Hilse, J. Banks, J. W. Gary, H. J. Burckhart, Jacqueline Batley, T. Mouthuy, S. J. Hillier, P. Paschievici, T. Kobayashi, C. J. Virtue, N. J. Tresilian, P. S. Wells, Terry Richard Wyatt, Marcello Mannelli, J. E. Duboscq, R. D. Heuer, R. G. Kellogg, J. von Krogh, O. Runolfsson, Andris Skuja, Fabrizio Fabbri, M. Coupland, R. J. Barlow, D. Van den plas, G. T. Zorn, O. Schaile, S. Barnett, D. J. Miller, D. S. Koetke, A. D. Schaile, John Hobbs, Tetsuro Mashimo, Dave Robinson, Stefano Marcellini, T. Wlodek, Tohru Takeshita, M. H. Lehto, L. A. del Pozo, James Letts, N. J. Thackray, V. H. Winterer, A. M. Rossi, T. Tsukamoto, S. Levegrün, K. Stephens, Michael Dittmar, F. Lamarche, Claudio Grandi, Georges Azuelos, P. F. Harrison, W. Gorn, M. J. Oreglia, A. Yeaman, J. Mildenberger, Harold Nguyen, R. J. Hemingway, M. A. Thomson, J. F. Kral, K. W. Bell, G. A. Bahan, D. Pitman, A. A. Carter, P. Singh, N. K. Watson, Stephen Lloyd, P. M. Hattersley, Max Weber, M. Tecchio, C. Moisan, J. P. Walker, R. Van Kooten, V. Gibson, P. Berlich, P. Jovanovic, A. Gaidot, M. Sproston, L. Köpke, W. J. Collins, M. Hauschild, J. C. Hill, Misao Sasaki, G. A. Beck, J. R. Carter, Austin Ball, R. W. L. Jones, G. N. Patrick, John Baines, G. D. Lafferty, P. Poffenberger, R. Lahmann, D. Menszner, P. Teixeira-Dias, Phillip Allport, S. W. O'Neale, B. Panzer-Steindel, S. Schreiber, P. Routenburg, C. Markus, C. J. Oram, N. Tesch, A. Dieckmann, Alessandro Montanari, T. W. Pritchard, T. J. McMahon, K. J. Anderson, G. P. Siroli, J. Schwiening, D. R. Ward, J. P. Martin, R. K. Carnegie, P. A. Elcombe, J. Hagemann, D. C. Imrie, H. Przysiezniak, B. Schmitt, J. C. Clayton, J. A. Wilson, S. De Jong, M. Fierro, M. Yurko, M. Rosvick, J. Becker, W. Schappert, A. Wagner, P. W. Jeffreys, A. M. Lee, C. Wahl, G. J. VanDalen, L. Levinson, R. Shypit, M. Hansroul, C. Jui, J. E. Pilcher, D. Lellouch, C. H. Shepherd-Themistocleous, R. J. Homer, J. M. Lorah, W. Mohr, Gideon Alexander, Paolo Capiluppi, D. A. Hinshaw, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, R. W. Springer, J. Ludwig, K. Runge, P. Bock, G. Duckeck, R. Ströhmer, F. Odorici, H. M. Bosch, Wolfram Dietrich Zeuner, G. Mikenberg, H. Mes, I. P. Duerdoth, M. Kwano, J. M. Roney, I. J. Bloodworth, M. Settles, M. Foucher, G. W. Wilson, D. Karlen, A. K. Honma, T. J. Smith, P. Mättig, C. M. Hawkes, M. Cooper, Takehiko Mori, P. D. Acton, E. Duchovni, Erez Etzion, Stefan Kluth, S. Rossberg, J. G. Layter, R. P. Middleton, S. Wotton, G. G. Hanson, J. Goldberg, B. Nellen, P. Leblanc, G. Giacomelli, H. G. Evans, M. J. Goodrick, I. Cohen, P. Schenk, M. S. Dixit, and Frans Meijers
Subjects: Nuclear physics, Physics, Hadronic decay, Nuclear and High Energy Physics, Meson, Silicon, chemistry, Electron–positron annihilation, Hadron, chemistry.chemical_element, Particle Physics - Experiment
Abstract: From a data sample of approximately 240 000 hadronic Z 0 decays recorded during 1991 a sample of about 130 semileptonic B hadron decays containing a D 0 , D + or D ∗+ has been isolated. Using silicon microvertex detector information the decay vertices in these events have been reconstructed. The average B hadron lifetime of the mix of B hadrons in this event sample is measured to be 1.51 −0.14 +0.16 ±0.11 ps. From the distribution of decay times in the different samples the lifetimes of the B 0 and B + mesons are determined to be 1.51 −0.23−0.14 +0.24+0.12 ps and 1.51 −0.28−0.14 +0.30+0.12 ps, respectively. The measured ratio of the B + to B 0 lifetimes of 1.00 −0.25 +0.33 ±0.08 supports expectations that the lifetimes are similar.
Published: 1993

18. Measurement of the averageb hadron lifetime inZ 0 decays

Author: J. Mildenberger, Harold Nguyen, A. Astbury, G. Beaudoin, C. Moisan, G. A. Beck, U. Müller, A. J. Martin, Erez Etzion, Achim Stahl, P. Teixeira-Dias, Tohru Takeshita, I. J. Bloodworth, Shlomo Dado, K. Stephens, Stefan Kluth, A. Skillman, J. R. McNutt, F. S. Merritt, B. Schmitt, Shlomit Tarem, J. G. Layter, Georges Azuelos, A. Gaidot, M. Kuwano, T. Wlodek, D. Axen, C. K. Hargrove, M. Settles, X. C. Lou, A. Jawahery, F. Odorici, M. Sproston, J. F. Kral, K. W. Bell, R. Batoldus, V. Gibson, H. Takeda, G. Quast, Madjid Boutemeur, James Pinfold, D. G. Fong, J. Hart, J. D. Gillies, F. G. Oakham, D. Pitman, S. Rossberg, C. J. Oram, John Baines, T. J. McMahon, M. Foucher, D. J. Miller, J. Gascon, H. von der Schmitt, Gideon Bella, P. Routenburg, N. I. Geddes, Max Weber, Peter Sherwood, F. Lamarche, Margret Fincke-Keeler, Matthias Schröder, Giora Mikenberg, P. Jovanovic, H. J. Burckhart, Sachio Komamiya, C. Jui, Austin Ball, M. H. Lehto, P. G. Estabrooks, R. K. Keeler, N. Tesch, A. Dieckmann, D. Menszner, E. Ros, A. T. Watson, Alessandro Montanari, Paul Kyberd, F. K. Loebinger, J. C. Hill, Misao Sasaki, R. W. Springer, Alexander Wagner, Gideon Alexander, H. Lafoux, R. P. Middleton, Otmar Biebel, Paolo Capiluppi, S. L. Chu, Marcello Mannelli, J. E. Duboscq, G. W. Wilson, D. R. Ward, G. E. Richards, D. E. Plane, C. Y. Chang, J. Schwiening, D. Karlen, C. Burgard, J. Hagemann, J. Ludwig, B. C. Shen, Andris Skuja, T. G. Shears, J. A. McKenna, N. Paz-Jaoshvili, G. Transtromer, D. G. Charlton, D. L. Wagner, B. Boden, K. Runge, Gunter Wolf, A. D. Schaile, Tetsuro Mashimo, P. Bentkowski, T. P. Kokott, P. M. Watkins, P. Igo-Kemenes, P. A. Elcombe, R. K. Carnegie, A. Luig, P. Bock, J. P. Martin, B. Poli, A. K. Honma, Ehud Duchovni, V. H. Winterer, C. M. Hawkes, M. Cooper, M. W. Redmond, P. M. Hattersley, H. Deng, R. Humbert, Daniel Lellouch, J. R. Batley, D. M. Gingrich, Silvia Arcelli, G. A. Snow, C. P. Ward, D. J.P. Dumas, S. De Jong, W. G. Scott, H. Ihssen, H. Jeremie, W. Gorn, P. Pfister, A. Rollnik, R. Giacomelli, J. A. Wilson, H. M. Fischer, D. L. Rees, Takehiko Mori, John Hobbs, W. R. Gibson, J. Becker, S. W. Gensler, R. Kowalewski, R. Lahmann, H. Mes, U. Maur, P. Berlich, A. Michelini, A. C. Janissen, S. Wotton, S. J. Hillier, T. Kobayashi, C. J. Virtue, L. Köpke, J. C. Clayton, D. C. Imrie, D. A. Hinshaw, P. Scharff-Hansen, J. W. Gary, W. Schappert, Randall Sobie, G. D. Lafferty, A. Beck, I. P. Duerdoth, M. J. Losty, J. M. Roney, S. A. Robins, A. M. Smith, E. Heflin, P. E.L. Clarke, T. W. Pritchard, Norbert Wermes, Sherry Towers, G. P. Siroli, Christoph Schwick, J. Steuerer, D. R. Rust, G. Vasseur, B. Lorazo, J. Goldberg, R. M. Brown, Lorne Levinson, G. J. VanDalen, M. Morii, M. Jimack, Peter R Hobson, M. J. Pearce, Horst Breuker, B. Nellen, P. F. Harrison, G. M. Dallavalle, E. do Couto e Silva, P. Leblanc, P. D. Acton, Stephen Lloyd, M. Tecchio, E. Torrente-Lujan, Roger Barlow, John Allison, G. G. Hanson, R. E. Hughes-Jones, H. O. Ogren, T. Behnke, Kiyotomo Kawagoe, Christoph Geich-Gimbel, S. Orito, M. Rosvick, M. Hansroul, H. G. Evans, M. J. Goodrick, R. Yaari, J. von Krogh, A. M. Lee, T. J. Smith, S. Bethke, Marco Cuffiani, I. Cohen, R. Mir, P. Schenk, P. Weber, J. E. Conboy, R. G. Kellogg, M. S. Dixit, A. Yeaman, Frans Meijers, Dave Robinson, D. S. Koetke, A. M. Rossi, N. K. Watson, J. M. Lorah, C. H. Shepherd-Themistocleous, L. A. del Pozo, C. Sbarra, T. Tsukamoto, Stefano Marcellini, S. Levegrün, J. Kroll, R. J. Homer, G. Duckeck, R. Ströhmer, James Letts, W. Mohr, P. Mättig, Michael Dittmar, G. Yekutieli, F. X. Gentit, G. T. Zorn, A. A. Carter, M. J. Oreglia, Roger Jones, R. Van Kooten, H. M. Bosch, Wolfram Dietrich Zeuner, A. Pouladdej, B. Fabbro, J. R. Carter, B. Panzer-Steindel, G. N. Patrick, G. Giacomelli, J. Banks, N. J. Tresilian, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, S. Barnett, D. Hochman, M. Yurko, P. W. Jeffreys, P. Bright-Thomas, R. J. Hemingway, M. A. Thomson, T. Hilse, O. Runolfsson, C. Beeston, Claudio Grandi, H. Przysiezniak, M. Fierro, P. Poffenberger, M. Hauschild, C. Markus, P. Paschievici, F. C. Grant, R.J. Akers, O. Schaile, M. A. Whalley, Gregor Herten, C. Wahl, B. Wilkens, J. E. Pilcher, S. W. O'Neale, K. J. Anderson, M. F. Turner, B. W. Kennedy, A. Buijs, D. M. Strom, C. Stegmann, Tatsuo Kawamoto, M. Jones, Claude Leroy, J. P. Pansart, P. S. Wells, Terry Richard Wyatt, and M. Coupland
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Physics and Astronomy (miscellaneous), Maximum likelihood, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Detector, Elementary particle, Electron, Nuclear physics, High Energy Physics::Experiment, Quantum field theory, Engineering (miscellaneous), Particle Physics - Experiment, Lepton
Abstract: A sample of 2610 electron candidates and 2762 muon candidates identified in hadronicZ0 decays has been used to measure the averageb hadron lifetime. These data were recorded with the OPAL detector during 1990 and 1991. Maximum likelihood fits to the distributions of the lepton impact parameters yield an averageb hadron lifetime of $$\tau _b = 1523 \pm 34 \pm 38fs$$ , where the first error is statistical and the second systematic. This result is a weighted average over the semileptonic branching fractions and production rates of theb hadrons produced inZ0 decays.
Published: 1993

19. Precision measurements of the neutral current from hadron and lepton production at LEP

Author: D. Pitman, M. H. Lehto, A. Astbury, H. O. Ogren, Christoph Geich-Gimbel, A. D. Schaile, O. Ganel, A. J. Martin, G. M. Dallavalle, J. E. Conboy, V. H. Winterer, J. von Krogh, J. Kroll, C. Wahl, C. K. Hargrove, P. E.L. Clarke, Dave Robinson, F. X. Gentit, L. A. del Pozo, P. Berlich, J. E. Pilcher, B. Boden, Kiyotomo Kawagoe, J. C. Clayton, J. Steuerer, P. M. Hattersley, A. Pouladdej, T. Hilse, L. Köpke, C. Moisan, J. P. Walker, G. A. Beck, B. Poli, Tohru Takeshita, P. Weber, S. Wotton, A. Simon, Otmar Biebel, G. E. Richards, James Pinfold, Michael Dittmar, G. Yekutieli, O. Runolfsson, P. Teixeira-Dias, J. R. Batley, P. S. Wells, Georges Azuelos, D. G. Charlton, D. L. Wagner, N. Paz-Jaoshvili, S. J. Hiller, R. Lahmann, D. C. Imrie, D. G. Fong, F. Lamarche, A. A. Carter, R. Van Kooten, G. P. Siroli, Christoph Schwick, T. Mouthuy, Terry Richard Wyatt, B. Schmitt, J. M. Lorah, J. Goldberg, K. W. Bell, N. I. Geddes, Max Weber, H. Deng, R. Humbert, Paul Kyberd, F. K. Loebinger, M. Coupland, F. S. Merritt, Silvia Arcelli, W. Mohr, O. Schaile, J. Gascon, H. von der Schmitt, B. Nellen, W. J. Collins, P. Leblanc, G. T. Zorn, J. Banks, Randall Sobie, J. C. Hill, Misao Sasaki, B. C. Shen, H. Mes, R. Yaari, M. W. Redmond, S. Bethke, Tara Shears, P. A. Elcombe, G. D. Lafferty, A. Rollnik, R. Giacomelli, P. Igo-Kemenes, G. Maringer, R. D. Heuer, Fabrizio Fabbri, C. Leroy, A. K. Honma, Richard Keeler, I. P. Duerdoth, Marco Cuffiani, D. E. Plane, C. Y. Chang, Margret Fincke-Keeler, S. Schreiber, T. J. McMahon, J. F. Kral, Horst Breuker, H. Jeremie, D. Van den plas, R. E. Hughes-Jones, A. M. Rossi, T. W. Pritchard, P. Jovanovic, H. G. Evans, J. Becker, P. F. Harrison, W. G. Scott, M. J. Goodrick, I. Cohen, Norbert Wermes, Claudio Grandi, Austin Ball, D. Menszner, G. J. VanDalen, S. W. O'Neale, J. Schwiening, R. K. Carnegie, U. Maur, J. A. McKenna, D. R. Rust, P. D. Acton, Stephen Lloyd, G. A. Snow, C. P. Ward, T. Tsukamoto, K. J. Anderson, R. Kowalewski, S. Levegrün, H. M. Fischer, M. Tecchio, P. Bentkowski, S. L. Chu, S. Barnett, J. Mildenberger, J. P. Pansart, Marcello Mannelli, J. E. Duboscq, Andris Skuja, J. A. Wilson, Harold Nguyen, E. do Coto e Silva, D. L. Rees, A. Michelini, M. A. Thomson, P. Pfister, Alessandro Montanari, A. C. Janissen, M. J. Losty, S. Orito, M. Rosvick, D. Hochman, N. J. Thackray, A. Gaidot, M. F. Turner, M. Kuwano, T. Wlodek, Ehud Duchovni, R. Shypit, R. F. McGowan, P. Taras, J. M. Roney, M. Sproston, Erez Etzion, Tetsuro Mashimo, Stefan Kluth, Shlomit Tarem, M. Hauschild, F. C. Grant, M. A. Whalley, P. Routenburg, N. Tesch, A. Dieckmann, R. Mir, Alan Watson, Mitsuaki Nozaki, W. Schappert, G. Beaudoin, K. Stephens, B. W. Kennedy, J. R. McNutt, H. Ihssen, C. Markus, S. Rossberg, C. J. Oram, P. Paschievici, W. Gorn, John Hobbs, D. J.P. Dumas, G. A. Bahan, M. Jimack, John Allison, P. G. Estabrooks, S. W. Gensler, R. P. Middleton, T. Kobayashi, V. Gibson, F. Odorici, A. Buijs, C. J. Virtue, G. Quast, M. Jobes, U. Binder, P. Poffenberger, C. Jui, P. Scharff-Hansen, W. R. Gibson, Shlomo Dado, M. J. Oreglia, M. Hansroul, D. M. Strom, John Baines, R. G. Kellogg, J. W. Gary, F. G. Oakham, A. M. Smith, P. M. Watkins, Phillip Allport, A. Beck, E. Heflin, C. H. Shepherd-Themistocleous, G. Vasseur, X. C. Lou, B. Lorazo, J. Hart, Tatsuo Kawamoto, R. J. Homer, R. M. Brown, D. S. Koetke, Lorne Levinson, Stefano Marcellini, J. R. Carter, G. N. Patrick, J. D. Gillies, Giora Mikenberg, D. R. Ward, G. Transtromer, E. Torrente-Lujan, Roger Barlow, Gideon Alexander, Paolo Capiluppi, D. J. Miller, James Letts, J. G. Layter, H. Przysiezniak, M. Fierro, M. Yurko, P. W. Jeffreys, J. P. Martin, A. M. Lee, S. De Jong, P. Bright-Thomas, R. J. Hemingway, G. G. Hanson, P. Schenk, M. S. Dixit, Frans Meijers, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, Sachio Komamiya, N. J. Tresilan, R. W. Springer, Alexander Wagner, E. Ros, P. Singh, J. Hagemann, R. W. L. Jones, T. P. Kokott, Carla Sbarra, C. M. Hawkes, M. Cooper, Daniel Lellouch, J. Ludwig, K. Runge, P. Bock, Takehiko Mori, B. Panzer-Steindel, G. Giacomelli, Gideon Bella, H. J. Burckhart, D. A. Hinshaw, A. Yeaman, N. K. Watson, T. J. Smith, T. Behnke, P. Mättig, I. J. Bloodworth, M. Morii, Peter R Hobson, M. Settles, M. Foucher, G. Duckeck, G. W. Wilson, R. Ströhmer, D. Karlen, C. Burgard, H. M. Bosch, and Wolfram Dietrich Zeuner
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Neutral current, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Electroweak interaction, Nuclear physics, Pair production, High Energy Physics::Experiment, Born approximation, Engineering (miscellaneous), Particle Physics - Experiment, Bhabha scattering, Lepton
Abstract: New measurements of the hadronic and leptonic cross sections and of the leptonic forward-backward asymmetries ine+e− collisions are presented. The analysis includes data recorded up to the end of 1991 by the OPAL experiment at LEP, with centre-of-mass energies within ±3 GeV of the Z0 mass. The results are based on a recorded total of 454 000 hadronic and 58 000 leptonic events. A model independent analysis of Z0 parameters based on an extension of the improved Born approximation is presented leading to test of lepton universality and an interpretation of the results within the Standard Model framework. The determination of the mass and width of the Z0 benefit from an improved understanding of the LEP energy calibration.
Published: 1993

20. QCD coherence studies using two particle azimuthal correlations

Author: P. Singh, M. Hauschild, C. Markus, P. Paschievici, T. R. Wyatt, Silvia Arcelli, R. W. L. Jones, M. Hansroul, H. Przysiezniak, P. Le Du, J. C. Clayton, B. Panzer-Steindel, Sachio Komamiya, E. Ros, J. P. Martin, J. Hart, G. Beaudoin, G. Giacomelli, Andris Skuja, C. Wahl, J. D. Gillies, C. P. Howarth, C. H. Shepherd-Themistocleous, J. E. Pilcher, Tetsuro Mashimo, M. Jimack, John Allison, O. Schaile, R. J. Homer, D. Axen, A. Jawahery, S. De Jong, Gideon Bella, Tohru Takeshita, T. J. Smith, D. J. Miller, Shlomo Dado, T. Hilse, A. Simon, T. P. Kokott, Carla Sbarra, Otmar Biebel, G. Tysarczyk-Niemeyer, P. Mättig, O. Runolfsson, G. E. Richards, P. M. Watklins, F. C. Grant, D. G. Charlton, D. L. Wagner, P. Poffenberger, M. A. Whalley, F. S. Merritt, F. Lamarche, C. Moisan, J. P. Walker, Peter Sherwood, Georges Azuelos, W. Gorn, C. M. Hawkes, M. Cooper, Daniel Lellouch, X. C. Lou, R. Van Kooten, P. A. Elcombe, R. W. Springer, Alexander Wagner, D. Pitman, P. Teixeira-Dias, J. F. Kral, K. W. Bell, G. A. Bahan, Takehiko Mori, Claudio Grandi, N. I. Geddes, Max Weber, H. Deng, R. Humbert, G. D. Lafferty, H. Mes, P. Jovanovic, D. C. Imrie, A. Buijs, Giora Mikenberg, J. C. Hill, M. H. Lehto, Austin Ball, D. Menszner, I. P. Duerdoth, M. Yurko, Misao Sasaki, D. M. Strom, P. W. Jeffreys, B. C. Shen, I. J. Bloodworth, C. Jui, J. Hagemann, P. Igo-Kemenes, J. Ludwig, K. Runge, P. Bock, T. Mouthuy, A. M. Lee, Tatsuo Kawamoto, Alessandro Montanari, H. J. Burckardt, R. G. Kellogg, Margret Fincke-Keeler, G. Maringer, A. K. Honma, M. Settles, R. J. Hemingway, P. G. Estabrooks, D. L. Rees, J. Becker, John Hobbs, Stefano Marcellini, W. G. Scott, D. G. Fong, M. Foucher, G. J. VanDalen, A. D. Schaile, James Letts, H. Jeremie, R. E. Hughes-Jones, U. Maur, R. Kowalewski, G. P. Siroli, J. Gascon, H. von der Schmitt, P. Pfister, G. W. Wilson, A. Astbury, K. J. Anderson, D. Karlen, G. A. Snow, C. P. Ward, S. Orito, M. Rosvick, R. Mir, J. A. McKenna, C. Burgard, G. T. Zorn, S. Wotton, F. G. Oakham, G. Duckeck, V. H. Winterer, Christoph Schwick, O. Ganel, J. Mildenberger, Harold Nguyen, V. Gibson, M. J. Losty, R. Ströhmer, P. Berlich, L. Köpke, E. do Couto e Silva, A. J. Martin, P. Taras, A. Yeaman, A. M. Rossi, P. S. Wells, Marcello Mannelli, J. E. Duboscq, Mitsuaki Nozaki, T. Tsukamoto, M. J. Oreglia, B. W. Kennedy, H. M. Fischer, J. Goldberg, P. E.L. Clarke, J. Steuerer, N. K. Watson, R. F. McGowan, M. Jobes, U. Binder, A. Michelini, A. C. Janissen, J. M. Lorah, M. Coupland, B. Nellen, J. Banks, P. Scharff-Hansen, Kiyotomo Kawagoe, W. J. Collins, Randall Sobie, W. Mohr, P. Leblanc, H. M. Bosch, Wolfram Dietrich Zeuner, Paul Kyberd, F. K. Loebinger, N. J. Tresilian, S. Weisz, G. N. Patrick, J. W. Gary, S. Bougerolle, R. D. Heuer, Fabrizio Fabbri, H. O. Ogren, D. Van den plas, Richard Keeler, M. W. Redmond, Christoph Geich-Gimbel, A. M. Smith, G. Vasseur, C. K. Hargrove, T. W. Pritchard, S. Levergrün, A. Rollnik, J. M. Roney, B. Lorazo, J. R. Carter, H. G. Evans, D. R. Rust, M. J. Goodrick, F. Odorici, J. E. Conboy, N. Paz-Jaoshvili, Claude Leroy, P. Lennert, Phillip Allport, I. Cohen, J. P. Pansart, P. Weber, J. Kroll, A. Gaidot, F. X. Gentit, R. Yaari, M. Kuwano, T. Wlodek, M. Sproston, S. Bethke, B. Boden, D. A. Hinshaw, Marco Cuffiani, P. Routenburg, B. Poli, A. Pouladdej, N. Tesch, A. Dieckmann, Erez Etzion, Tara Shears, J. R. Batley, D. E. Plane, C. Y. Chang, Stefan Kluth, Shlomit Tarem, M. Morii, S. W. O'Neale, Stephen Hillier, Peter R Hobson, T. Behnke, S. Rossberg, C. J. Oram, Gideon Alexander, R. P. Middleton, Horst Breuker, Paolo Capiluppi, P. Schenk, Alan Watson, D. J.P. Dumas, P. M. Hattersley, W. R. Gibson, A. Beck, P. F. Harrison, E. Heflin, P. D. Acton, Stephen Lloyd, R. M. Brown, M. Tecchio, Lorne Levinson, N. Wermes, Ehud Duchovni, R. Shypit, Roger Barlow, G. G. Hanson, E.J. Prebys, M. S. Dixit, Frans Meijers, H. Ihssen, S. W. Gensler, T. Kobayashi, C. J. Virtue, G. M. Dallavalle, J. von Krogh, Dave Robinson, L. A. del Pozo, Michael Dittmar, G. Yekutieli, A. A. Carter, S. Schreiber, T. J. McMahon, J. Schwiening, R. K. Carnegie, J. A. Wilson, W. Schappert, S. Barnett, D. Hochman, N. J. Thackray, K. Stephens, J. R. McNutt, G. Quast, John Baines, D. R. Ward, G. Transtromer, J. G. Layter, and M. F. Turner
Subjects: Quantum chromodynamics, Physics, Particle physics, Physics and Astronomy (miscellaneous), Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Monte Carlo method, Perturbative QCD, Parton, Nuclear physics, High Energy Physics::Experiment, Nuclear Experiment, Parton shower, Engineering (miscellaneous), Particle Physics - Experiment, Coherence (physics)
Abstract: From a sample of 146900 hadronicZ 0 decays recorded by the OPAL detector at LEP, we have studied the azimuthal correlations of particles in hadronic events. It is expected that these correlations are sensitive to interference effects in QCD. We have compared the data to QCD Monte Carlo models which include and which do not include interference effects. We find that the distributions of azimuthal correlations are not reproduced by the parton shower models we have tested unless interference effects are included, no matter which hadronisation scheme is used.
Published: 1993

21. Measurements of $$B^0 - \bar B^0 $$ mixing, $${{\Gamma (Z^0 \to b\bar b)} \mathord{\left/ {\vphantom {{\Gamma (Z^0 \to b\bar b)} {\Gamma (Z^0 \to hadrons)}}} \right. \kern-\nulldelimiterspace} {\Gamma (Z^0 \to hadrons)}}$$ and semileptonic branching ratios forb-flavoured hadrons in hadronicZ 0 decays

Author: F. S. Merritt, Sachio Komamiya, E. Ros, Otmar Biebel, G. E. Richards, D. G. Charlton, D. L. Wagner, Kiyotomo Kawagoe, H. Deng, R. Humbert, T. J. Smith, K. Stephens, Madjid Boutemeur, D. Pitman, M. H. Lehto, M. Yurko, S. A. Robins, J. R. McNutt, T. P. Kokott, A. Luig, B. Fabbro, B. Panzer-Steindel, A. Skillman, B. C. Shen, Gregor Herten, A. Gaidot, T. Wlodek, P. G. Estabrooks, M. Sproston, P. W. Jeffreys, T. G. Shears, N. Tesch, A. Dieckmann, T. Kobayashi, Norbert Wermes, Sherry Towers, P. Weber, Ehud Duchovni, R. K. Keeler, C. Wahl, A. K. Honma, W. G. Scott, B. Wilkens, T. Kawamoto, J. Steuerer, R. G. Kellogg, M. Jimack, P. Igo-Kemenes, R. Bartoldus, D. M. Gingrich, H. Ihssen, J. M. Roney, D. S. Koetke, P. M. Watkins, J. W. Gary, J. E. Pilcher, H. O. Ogren, S. Orito, H. Jeremie, W. R. Gibson, G. Quast, J. M. Lorah, M. Rosvick, John Baines, Gideon Bella, R. E. Hughes-Jones, U. Maur, Stefano Marcellini, S. W. Gensler, M. Hansroul, P. Bright-Thomas, R. Kowalewski, C. Sbarra, M. Jones, Christoph Geich-Gimbel, S. J. Hillier, R. Mir, James Letts, C. J. Virtue, P. Berlich, H. J. Burckhart, Jacqueline Batley, V. Gibson, L. Köpke, H. M. Fischer, M. J. Losty, R. J. Sobie, R.J. Akers, C. H. Shepherd-Themistocleous, A. Beck, M. A. Thomson, W. Mohr, E. Heflin, D. R. Ward, G. Transtromer, J. Kroll, R. M. Brown, D. R. Rust, E. do Couto e Silva, G. J. VanDalen, Michael Dittmar, T. Behnke, P. A. Elcombe, S. L. Lloyd, J. Mildenberger, R. J. Homer, Lorne Levinson, F. X. Gentit, J. E. Conboy, Harold Nguyen, Claude Leroy, G. G. Hanson, A. Michelini, A. C. Janissen, J. C. Clayton, G. Yekutieli, B. W. Kennedy, M. J. Oreglia, P. M. Hattersley, J. Becker, J. P. Pansart, Gilles Beaudoin, E. Torrente-Lujan, T. Hilse, P. F. Harrison, R. Yaari, Silvia Arcelli, F. Scharf, M. Tecchio, Margret Fincke-Keeler, N. I. Geddes, F. C. Grant, A. Yeaman, S. Bethke, O. Runolfsson, M. W. Redmond, A. M. Lee, G. Giacomelli, N. K. Watson, A. A. Carter, M. A. Whalley, Marco Cuffiani, R. Van Kooten, P. Mättig, P. Pfister, Erez Etzion, R. Lahmann, D. C. Imrie, C. Beeston, P. Schenk, E. Lefebvre, C. M. Hawkes, Claudio Grandi, A. Buijs, D. M. Strom, C. Stegmann, M. Cooper, Daniel Lellouch, G. N. Patrick, Gideon Alexander, Stefan Kluth, M. Hauschild, M. S. Dixit, Frans Meijers, M. Sasaki, Takehiko Mori, Paolo Capiluppi, S. L. Chu, Tohru Takeshita, M. G. Rison, F. Odorici, C. Markus, T. W. Pritchard, P. Paschievici, J. R. Carter, G. P. Siroli, J. King, Paul Kyberd, F. K. Loebinger, Christoph Schwick, P. E.L. Clarke, Shlomit Tarem, J. P. Martin, M. Morii, D. E. Plane, O. Schaile, Georges Azuelos, Peter R Hobson, C. Moisan, G. A. Beck, Achim Stahl, P. Teixeira-Dias, J. F. Kral, G. D. Lafferty, P. Bentkowski, P. Routenburg, S. De Jong, G. M. Dallavalle, S. W. O'Neale, P. S. Wells, K. W. Bell, Max Weber, A. Rollnik, P. Poffenberger, R. Giacomelli, J. C. Hill, J. von Krogh, I. J. Bloodworth, J. Banks, N. J. Tresilian, John Hobbs, J. A. McKenna, D. J.P. Dumas, Terry Richard Wyatt, A. T. Watson, S. Rossberg, C. J. Oram, B. Schmitt, R. J. Barlow, H. Przysiezniak, M. Settles, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, M. Coupland, K. J. Anderson, Dave Robinson, A. M. Rossi, T. Tsukamoto, S. Levegrün, M. Fierro, R. P. Middleton, M. Foucher, S. Barnett, C. Y. Chang, J. G. Layter, M. F. Turner, G. W. Wilson, D. Karlen, L. A. del Pozo, C. Burgard, T. J. McMahon, D. Hochman, J. Schwiening, B. Boden, C. Jui, B. Poli, R. K. Carnegie, H. Mes, J. A. Wilson, J. Goldberg, I. P. Duerdoth, B. Nellen, W. Schappert, A. D. Schaile, G. Mikenberg, P. Leblanc, V. H. Winterer, H. G. Evans, M. J. Goodrick, I. Cohen, Gunter Wolf, James Pinfold, D. G. Fong, S. Wotton, J. Gascon, H. von der Schmitt, Marcello Mannelli, J. E. Duboscq, R. W.L. Jones, Andris Skuja, Tetsuro Mashimo, W. Gorn, P. Scharff-Hansen, A. M. Smith, G. Vasseur, B. Lorazo, F. Lamarche, R. J. Hemingway, P. Jovanovic, Austin Ball, D. Menszner, Alessandro Montanari, J. Hart, J. D. Gillies, D. J. Miller, J. Lauber, H. Takeda, F. G. Oakham, G. A. Snow, C. P. Ward, D. L. Rees, M. J. Pearce, Horst Breuker, Shlomo Dado, X. C. Lou, D. A. Hinshaw, A. Astbury, U. Müller, A. J. Martin, C. K. Hargrove, Matthias Schröder, H. Lafoux, N. Paz-Jaoshvili, J. Allison, G. Duckeck, R. Ströhmer, G. T. Zorn, H. M. Bosch, Wolfram Dietrich Zeuner, D. Axen, A. Jawahery, Peter Sherwood, R. W. Springer, Alexander Wagner, J. Hagemann, J. Ludwig, K. Runge, and P. Bock
Subjects: Quark, Physics, Particle physics, Muon, Physics and Astronomy (miscellaneous), Branching fraction, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, High Energy Physics::Experiment, Engineering (miscellaneous), Energy (signal processing), Boson, Bar (unit)
Abstract: From a sample of about 450 000 hadronicZ0 decays, measurements of the average$B^0 - \bar B^0 $ mixing parameter, χ, the branching fraction ofZ0 bosons into hadrons containing bottom quarks,${{\Gamma (Z^0 \to b\bar b)} \mathord{\left/ {\vphantom {{\Gamma (Z^0 \to b\bar b)} {\Gamma (Z^0 \to hadrons)}}} \right. \kern-\nulldelimiterspace} {\Gamma (Z^0 \to hadrons)}}$, the average semileptonic branching ratios for such hadrons,B(b→l) andB(b→c→l), and the mean scaled energy of these hadrons, 〈xE〉, are presented. The measurements were obtained using a simultaneous fit to single-lepton and dilepton events collected with the OPAL detector at LEP, including both electrons and muons. The results are where the errors are statistical and systematic, respectively, in each case. The result forB)b→c→l) excludes decays of the typeb→→l.
Published: 1993

22. Evidence for chain-like production of strange baryon pairs in jets

Author: T. P. Kokott, G. Tysarczyk-Niemeyer, F. X. Gentit, A. Beck, C. Markus, S. Komamiya, W. R. Gibson, G. G. Hanson, S. Dado, John Hobbs, A. M. Lee, F. Odorici, G. A. Snow, C. P. Ward, T. Hilse, J. Schwiening, F. S. Merritt, T. Mashimo, G. W. Wilson, H. O. Ogren, D. L. Rees, K. Stephens, D. Pitman, A. Dieckmann, J. E. Conboy, J. Kroll, S. Bethke, Tara Shears, R. M. Brown, R. J. Hemingway, S. Rossberg, H. Jeremie, Andris Skuja, S. Barnett, J. A. McKenna, H. M. Fischer, M. W. Redmond, W. Mohr, Frans Meijers, Peter R Hobson, G. Duckeck, P. Routenburg, E. Heflin, P. E.L. Clarke, A. Simon, C. Wahl, F. G. Oakham, J. Letts, G. Quast, E. Duchovni, A. Wagner, M. Morii, T. Mori, Horst Breuker, P. A. Elcombe, B. Lorazo, Otmar Biebel, G. N. Patrick, E. do Couto e Silva, M. Cooper, T. Mouthuy, J. Ludwig, A. Yeaman, J. Pinfold, P. M. Watkins, D. C. Imrie, S. Tarem, A. Gaidot, D. Menszner, M. Hansroul, H. G. Evans, T. J. McMahon, P. Weber, D. G. Charlton, D. L. Wagner, M. J. Goodrick, S. De Jong, S. Levegrün, J. Hart, Tohru Takeshita, P. Sherwood, H. M. Bosch, F. Lamarche, M. Yurko, P. Mättig, D. Hochman, W. J. Collins, P. Pfister, H. Przysiezniak, H. Deng, Harold Nguyen, N. K. Watson, P. Bentkowski, J. P. Martin, J. D. Gillies, C. Moisan, G. T. Zorn, M. Jimack, B. Panzer-Steindel, C. Jui, Richard Keeler, G. Beaudoin, T. J. Smith, M. Sasaki, P. Berlich, X. C. Lou, R. Humbert, J. Mildenberger, D. E. Plane, C. Y. Chang, S. Marcellini, J. F. Kral, G. P. Siroli, D. R. Rust, J. C. Clayton, N. Paz-Jaoshvili, P. G. Estabrooks, K. J. Anderson, P. Poffenberger, I. Cohen, C. M. Hawkes, A. Pouladdej, R. E. Hughes-Jones, M. Coupland, C. Burgard, V. Gibson, John Baines, P. Bock, O. Runolfsson, E. Ros, G. Giacomelli, Gideon Bella, J. Hagemann, R. K. Carnegie, C. Leroy, A. C. Janissen, N. I. Geddes, G. Yekutieli, G. Transtromer, M. Kuwano, U. Binder, B. C. Shen, R. Lahmann, W. Schappert, J. C. Hill, H. J. Burckhart, A. Michelini, B. Poli, Carla Sbarra, A. Jawahery, J. P. Pansart, J. R. McNutt, E. Etzion, J. Becker, U. Maur, M. Fierro, T. W. Pritchard, John Allison, R. G. Kellogg, D. S. Koetke, R. W.L. Jones, R. W. Springer, D. R. Ward, B. Boden, P. W. Jeffreys, M. F. Turner, R. Yaari, Mitsuaki Nozaki, B. W. Kennedy, S. Arcelli, V. H. Winterer, G. M. Dallavalle, S. L. Chu, P. Igo-Kemenes, J. von Krogh, P. F. Harrison, H. Mes, Dave Robinson, G. Azuelos, L. A. del Pozo, G. A. Bahan, M. Hauschild, Alan Watson, P. Kyberd, P. D. Acton, R. F. McGowan, C. K. Hargrove, J. A. Wilson, W. G. Scott, A. Rollnik, M. J. Losty, J. M. Lorah, M. Sproston, A. M. Rossi, M. Jobes, G. D. Lafferty, A. J. Martin, P. Leblanc, D. Lellouch, I. P. Duerdoth, C. H. Shepherd-Themistocleous, H. Ihssen, F. K. Loebinger, M. A. Thomson, J. G. Layter, R. Kowalewski, S. Wotton, R. Ströhmer, L. Levinson, M. Rosvick, G. Alexander, P.P. Singh, F. C. Grant, W. Gorn, P. Bright-Thomas, A. Buijs, Kiyotomo Kawagoe, D. M. Strom, C. Grandi, Tatsuo Kawamoto, O. Schaile, S. Schreiber, R. Giacomelli, K. Runge, N. J. Tresilian, B. Nellen, R. Van Kooten, D. J. Miller, M. Dittmar, J. Steuerer, T. Kobayashi, M. Fincke-Keeler, D. Karlen, J. Goldberg, D. Axen, P. Paschievici, A. K. Honma, C. J. Oram, O. Ganel, G. Vasseur, M. Weber, R. Mir, M. Settles, M. Foucher, M. J. Oreglia, T. Wlodek, P. Schenk, J. E. Pilcher, Wolfram Dietrich Zeuner, G. Maringer, N. J. Thackray, M. H. Lehto, G. J. VanDalen, E. Torrente-Lujan, Roger Barlow, M. Cuffiani, G. A. Beck, Ian J Bloodworth, A. A. Carter, G. E. Richards, A. Astbury, P. M. Hattersley, S. Orito, T. Tsukamoto, Austin Ball, A. Montanari, P. Jovanovic, J. Banks, J. R. Carter, N. Tesch, C. J. Virtue, M. A. Whalley, G. Mikenberg, T. R. Wyatt, S. W. O'Neale, L. Köpke, Stefan Kluth, J. R. Batley, R. Sobie, R. P. Middleton, C. Geich-Gimbel, P. S. Wells, R. J. Homer, R. Shypit, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, T. Behnke, J. P. Walker, D. G. Fong, J. Gascon, H. von der Schmitt, J. M. Roney, Marcello Mannelli, J. E. Duboscq, N. Wermes, P. Scharff-Hansen, P. Teixeira-Dias, B. Schmitt, J. W. Gary, A. M. Smith, D. J.P. Dumas, D. A. Hinshaw, A. D. Schaile, K. W. Bell, Stephen Lloyd, M. Tecchio, S. W. Gensler, S. J. Hillier, P. Taras, Phillip Allport, Paolo Capiluppi, C. Schwick, and M. S. Dixit
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Electron–positron annihilation, High Energy Physics::Phenomenology, Nuclear Theory, Monte Carlo method, Hadron, Strangeness, Nuclear physics, Baryon, High Energy Physics::Experiment, Rapidity, Baryon number, Nuclear Experiment, Particle Physics - Experiment
Abstract: The production dynamics of baryon-antibaryon pairs are investigated using hadronic Z0 decays, recorded with the OPAL detector, which contain at least two identified Λ baryons. The rapidly difference for Λ Λ pairs shows the correlations expected from models with a chain-like production of baryon-antibaryon pairs. If the baryon number of a Λ is compensated by a Λ , the Λ is found with a probability of 53% in an interval of ±0.6 around the Λ rapidity. This correlation strength is weaker than predicted by the Herwig Monte Carlo and the Jetset Monte Carlo with a production chain of baryon-antibaryon, and stronger than predicted by the UCLA model. The observed rapidity correlations can be described by the Jetset Monte Carlo with a dominant production chain of baryon-meson-antibaryon, the popcorn mechanism. In addition to the short range correlations, one finds an indication of a correlation of Λ Λ pairs in opposite hemispheres if both the Λ and the Λ have large rapidities. Such long range correlations are expected if the primary quark flavours are compensated in opposite hemispheres and if these quarks are found in energetic baryons. Rates for simultaneous baryon and strangeness number compensation for Λ Λ , Ξ − Ξ + and Ξ − Λ ( Λ + Λ ) are measured and compared with different Monte Carlo models.
Published: 1993

23. A measurement of (892)± production in hadronic Z0 decays

Author: J. Steuerer, T. Kobayashi, M. Fincke-Keeler, P. D. Acton, S. Bethke, A. Astbury, P. M. Hattersley, J. Letts, G. Quast, E. Duchovni, L. Köpke, W. Mohr, D. R. Rust, P. A. Elcombe, J. Schwiening, S. J. Hillier, F. Odorici, P. Routenburg, C. Geich-Gimbel, J. Hart, R. Shypit, F. G. Oakham, S. Weisz, R. D. Heuer, Fabrizio Fabbri, Tara Shears, A. Simon, J. A. Wilson, D. Van den plas, P. Igo-Kemenes, K. Runge, E. Ros, R. M. Brown, S. Tarem, S. Levegrün, T. Mori, P. Bentkowski, T. J. McMahon, Otmar Biebel, D. G. Charlton, D. L. Wagner, N. J. Tresilian, G. Mikenberg, B. Nellen, P. S. Wells, G. Duckeck, C. M. Hawkes, A. Pouladdej, H. Przysiezniak, H. Deng, E. Torrente-Lujan, X. C. Lou, B. Poli, Tohru Takeshita, R. Humbert, S. W. O'Neale, W. Schappert, Carla Sbarra, Roger Barlow, R. J. Homer, G. G. Hanson, S. Dado, Horst Breuker, H. G. Evans, M. J. Goodrick, G. Beaudoin, S. Wotton, R. Ströhmer, D. Karlen, F. Lamarche, R. Yaari, M. H. Lehto, J. Goldberg, F. C. Grant, C. Markus, G. Giacomelli, T. Hilse, B. C. Shen, L. Levinson, W. Gorn, R. Sobie, G. N. Patrick, H. O. Ogren, S. Bougerolle, E.J. Prebys, P. Paschievici, C. J. Virtue, O. Ganel, S. Komamiya, J. F. Kral, A. M. Lee, D. Axen, D. Pitman, A. K. Honma, G. P. Siroli, N. I. Geddes, T. Wlodek, N. Tesch, Frans Meijers, P. Bright-Thomas, A. Buijs, D. M. Strom, T. P. Kokott, C. Grandi, T. R. Wyatt, S. Arcelli, S. Rossberg, H. Jeremie, M. Jimack, B. Panzer-Steindel, C. Jui, A. Dieckmann, J. E. Conboy, J. C. Hill, Tatsuo Kawamoto, M. Cooper, G. J. VanDalen, Stefan Kluth, S. Schreiber, W. J. Collins, Peter R Hobson, R. J. Hemingway, J. Banks, G. Tysarczyk-Niemeyer, F. X. Gentit, R. Mir, D. J. Miller, P. Weber, J. Kroll, C. J. Oram, F. K. Loebinger, Gideon Bella, G. Yekutieli, D. E. Plane, J. Ludwig, A. Yeaman, M. A. Thomson, E. do Couto e Silva, G. A. Snow, C. P. Ward, E. Heflin, D. L. Rees, K. Stephens, H. J. Burckhart, D. Hochman, J. Pinfold, Jacqueline Batley, Richard Keeler, C. K. Hargrove, M. J. Oreglia, P. Pfister, P. Sherwood, S. Marcellini, Ian J Bloodworth, C. Wahl, T. J. Smith, M. Cuffani, N. K. Watson, A. Beck, C. Moisan, P. M. Watkins, Alan Watson, G. Transtromer, G. Azuelos, D. J.P. Dumas, O. Runolfsson, A. Gaidot, S. Orito, F. S. Merritt, A. Rollnik, W. R. Gibson, M. Sasaki, A. Montanari, S. W. Gensler, R. K. Carnegie, C. Leroy, A. D. Schaile, J. R. Carter, John Hobbs, U. Binder, J. R. McNutt, Austin Ball, A. C. Janissen, C. Y. Chang, M. F. Turner, G. Vasseur, P. Berlich, S. De Jong, M. Weber, E. Etzion, J. Becker, U. Maur, T. Mashimo, M. J. Losty, P. Mättig, M. Sproston, M. Settles, G. A. Bahan, T. Tsukamoto, G. W. Wilson, Mitsuaki Nozaki, J. A. McKenna, J. P. Martin, M. Foucher, J. D. Gillies, J. Mildenberger, B. Lorazo, H. M. Fischer, R. E. Hughes-Jones, A. Wagner, M. Coupland, P. Schenk, B. W. Kennedy, D. C. Imrie, C. Burgard, M. A. Whalley, J. E. Pilcher, V. Gibson, V. H. Winterer, John Baines, G. M. Dallavalle, D. R. Ward, B. Boden, M. Hansroul, P. Teixeira-Dias, P. Taras, J. von Krogh, P. Poffenberger, P. F. Harrison, H. Mes, J. P. Pansart, Phillip Allport, Peter Clarke, Dave Robinson, L. A. del Pozo, M. Hauschild, J. C. Clayton, N. Paz-Jaoshvili, P. G. Estabrooks, I. Cohen, K. J. Anderson, P. Kyberd, W. G. Scott, T. W. Pritchard, John Allison, Paolo Capiluppi, C. Schwick, J. M. Lorah, A. M. Rossi, R. F. McGowan, M. S. Dixit, M. Jobes, G. D. Lafferty, Kiyotomo Kawagoe, P. Leblanc, R. G. Kellogg, D. S. Koetke, R. W.L. Jones, G. E. Richards, K. W. Bell, Stephen Lloyd, M. Tecchio, O. Schaile, D. Menszner, Harold Nguyen, R. P. Middleton, J. Hagemann, P. Bock, A. Michelini, M. Kuwano, R. Lahmann, G. Alexander, P.P. Singh, M. W. Redmond, M. Rosvick, H. M. Bosch, A. A. Carter, T. Mouthuy, G. T. Zorn, N. Wermes, P. Scharff-Hansen, B. Schmitt, J. W. Gary, A. M. Smith, M. Yurko, P. W. Jeffreys, D. A. Hinshaw, Wolfram Dietrich Zeuner, P. Jovanovic, J. P. Walker, D. G. Fong, A. Jawahery, J. Gascon, H. von der Schmitt, J. M. Roney, R. W. Springer, Marcello Mannelli, J. E. Duboscq, Andris Skuja, S. Barnett, A. J. Martin, D. Lellouch, T. Behnke, I. P. Duerdoth, C. H. Shepherd-Themistocleous, H. Ihssen, J. G. Layter, R. Kowalewski, G. Maringer, N. J. Thackray, R. Van Kooten, and M. Dittmar
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Cross section (physics), Particle physics, Meson, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, High Energy Physics::Experiment, Event (particle physics), Particle Physics - Experiment
Abstract: This is the post-print version of the Article - Copyright @ 1993 Elsevier. Measurements are presented of the inclusive cross section for K∗(892)± production in hadronic decays of the Z0 using a sample of about half a million events recorded with the OPAL experiment at LEP. Charged K∗ mesons are reconstructed in the decay channel K0Sπ±. A mean rate of 0.72±0.02±0.08 K∗ mesons per hadronic event is found. Comparison of the results with predictions of the JETSET and HERWIG models shows that JETSET overestimates the K∗± production cross section while HERWIG is consistent with the data. This study was supported by the Department of Energy, USA, National Science Foundation, USA, Science and Engineering Research Council, UK, Natural Sciences and Engineering Research Council, Canada, Israeli Ministry of Science, Minerva Gesellschaft, Japanese Ministry of Education, Science and Culture (the Monbusho) and a grant under the Monbusho International Science Research Program, American Israeli Bi-national Science Foundation, Direction des Sciences de la Matibre du Commissariat ~ l'Energie Atomique, France, Bundesministerium f'fir Forschung und Technologie, FRG, National Research Council of Canada, Canada, A.P. Sloan Foundation and Junta Nacional de Investigag~o Ciendfica e Tecnolrgica, Portugal.
Published: 1993

24. A study of the electric charge distributions of quark and gluon jets in hadronic Z0 decays

Author: T. W. Pritchard, D. E. Plane, J. Gascon, J. A. Wilson, Horst Breuker, K. Stephens, G. Yekutieli, R. Giacomelli, H. M. Bosch, S. Levegrün, M. Cuffiani, A. Jawahery, D. J. Miller, Tohru Takeshita, M. A. Thomson, I. Cohen, R. F. McGowan, Alan Watson, J. P. Walker, A. M. Rossi, Richard Keeler, J. Mildenberger, M. Weber, I. J. Bloodworth, R. Mir, G. D. Lafferty, R. W. Springer, John Carter, John Hobbs, D. J.P. Dumas, M. Jimack, M. Kuwano, P. Bright-Thomas, P. Kyberd, J. P. Pansart, J. F. Kral, J. Allison, J. Steuerer, D. Karlen, T. Wlodek, R. J. Hemingway, C. J. Oram, A. Gaidot, Gideon Bella, W. R. Gibson, S. W. O'Neale, H. J. Burckhart, P. M. Hattersley, A. Wagner, H. Przysiezniak, F. C. Grant, J. Hagemann, O. Runolfsson, R. Ströhmer, D. C. Imrie, S. Wotton, D. A. Hinshaw, B. Panzer-Steindel, E. Ros, R. J. Homer, J. Hart, A. Astbury, J. P. Martin, A. Rollnik, U. Maur, H. Mes, K. Runge, S. Kluth, G. Vasseur, W. Gorn, D. Hochman, P. Mättig, Carla Sbarra, P. Igo-Kemenes, R. D. Heuer, P. Berlich, B. C. Shen, R. W.L. Jones, J. C. Hill, J. D. Gillies, J. R. Batley, T. J. McMahon, M. A. Whalley, P. Bentkowski, P. A. Elcombe, J. C. Clayton, T. Kawamoto, T. Hilse, J. Pinfold, P. G. Estabrooks, N. Paz-Jaoshvili, D. Van den plas, T. Tsukamoto, A. Beck, D. Menszner, John Baines, J. Becker, G. G. Hanson, P. S. Wells, C. Geich-Gimbel, R. G. Kellogg, G. P. Siroli, J. M. Lorah, G. Transtromer, G. Alexander, A. Pouladdej, Phillip Allport, D. Lellouch, J. Letts, S. Orito, G. J. VanDalen, T. Behnke, Andris Skuja, J. Kroll, M. Dittmar, C. K. Hargrove, D. S. Koetke, G. Maringer, D. R. Ward, V. H. Winterer, R. M. Brown, P. M. Watkins, U. Binder, M. Yurko, T. R. Wyatt, R. J. Barlow, A. M. Lee, M. J. Oreglia, G. T. Zorn, M. Hansroul, B. Nellen, P. Taras, C. Moisan, J. Goldberg, O. Biebel, R. Sobie, S. Bethke, C. Burgard, P. Bock, A. Buijs, C. Schwick, G. Mikenberg, M. Sasaki, N. I. Geddes, T. P. Kokott, L. Levinson, P. Singh, D. M. Strom, S. Tarem, A. Dieckmann, C. J. Virtue, N. J. Tresilian, F. G. Oakham, D. R. Rust, A. A. Carter, T. Mashimo, A. J. Martin, R. P. Middleton, F. S. Merritt, J. E. Pilcher, T. J. Smith, F. X. Gentit, Austin Ball, K. J. Anderson, W. J. Collins, W. Schappert, S. Barnett, Maurice Goodrick, Paolo Capiluppi, E. Heflin, N. K. Watson, C. P. Ward, F. Lamarche, M. Nozaki, B. Schmitt, R. E. Hughes-Jones, G. W. Wilson, P. Poffenberger, O. Ganel, P. Routenburg, C. Wahl, B. Lorazo, J. W. Gary, Harold Nguyen, H. G. Evans, A. D. Schaile, C. Grandi, T. Mori, P. Weber, E. do Couto e Silva, L. Köpke, D. G. Charlton, D. L. Wagner, P. Teixeira-Dias, T. Kobayashi, G. Quast, G. Duckeck, G. Azuelos, W. G. Scott, J. A. McKenna, M. Hauschild, M. S. Dixit, A. Montanari, E. Torrente-Lujan, J. Ludwig, S. De Jong, Wolfram Dietrich Zeuner, H. Deng, S. Marcellini, C. M. Hawkes, J. Schwiening, C. Y. Chang, M. F. Turner, X. C. Lou, P. D. Acton, Stephen Lloyd, M. J. Losty, P. Scharff-Hansen, D. Axen, R. Yaari, P. Pfister, F. Odorici, E. Etzion, M. Rosvick, S. Arcelli, M. Tecchio, M. Coupland, P. Sherwood, G. A. Beck, C. Markus, G. Giacomelli, J. R. McNutt, A. Simon, P. Jovanovic, M. Cooper, H. M. Fischer, S. Rossberg, P. W. Jeffreys, M. Fincke-Keeler, A. M. Smith, H. O. Ogren, M. Settles, M. W. Redmond, R. Shypit, R. Kowalewski, O. Schaile, M. Sproston, G. N. Patrick, K. W. Bell, G. A. Bahan, S. W. Gensler, F. K. Loebinger, B. Poli, S. J. Hillier, M. H. Lehto, J. E. Conboy, P. E.L. Clarke, M. Fierro, D. G. Fong, H. von der Schmitt, H. Jeremie, J. G. Layter, N. Wermes, I. P. Duerdoth, A. Michelini, M. Foucher, P. Leblanc, M. Jobes, Marcello Mannelli, J. E. Duboscq, N. J. Thackray, B. W. Kennedy, T. Mouthuy, P. Paschievici, A. C. Janissen, J. M. Roney, R. Lahmann, H. Ihssen, A. Yeaman, S. Dado, A. K. Honma, S. Komamiya, P. R. Hobson, W. Mohr, Frans Meijers, R. Humbert, J. Banks, P. Schenk, E. Duchovni, G. A. Snow, D. L. Rees, C. Leroy, S. L. Chu, S. Schreiber, V. Gibson, C. Jui, G. Tysarczyk-Niemeyer, K. Kawagoe, P. F. Harrison, R. K. Carnegie, B. Boden, G. M. Dallavalle, J. von Krogh, C. H. Shepherd-Themistocleous, Dave Robinson, N. Tesch, L. A. del Pozo, G. Beaudoin, D. Pitman, G. E. Richards, R. Van Kooten, Franco Luigi Fabbri, and Tara Shears
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Charge conservation, High Energy Physics::Lattice, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, High Energy Physics::Phenomenology, Charge (physics), Jet (particle physics), Bottom quark, Electric charge, Gluon, Nuclear physics, High Energy Physics::Experiment, Particle Physics - Experiment, Lepton
Abstract: A sample of three-jet events containing a lepton with high momentum and transverse momentum is selected from hadronic decays of the Z0. The presence of the lepton indicates the semi-leptonic decay of a bottom quark and allows us, in combination with energy ordering of the jets, to distinguish between quark and gluon jets. The sign of the lepton charge is used to identify jets originating from positively and negatively charged quarks, for the jets with the lepton and for the high energy jets. Defining the jet charge by summing the charge of the particles assigned to a jet, it is observed that the mean jet charge of the quark jets is incompatible with zero and that the sign of the jet charge corresponds to that expected from the charge of the primary quark. In contrast, the mean charge of the gluon jets is consistent with zero.
Published: 1993

25. The forward-backward asymmetry of $$e^ + e^ - \to b\bar b and e^ + e^ - \to c\bar c$$ using leptons in hadronicZ 0 decays

Author: Madjid Boutemeur, Tohru Takeshita, James Pinfold, D. G. Fong, J. Gascon, H. von der Schmitt, S. L. Chu, P. G. Estabrooks, R. K. Keeler, Georges Azuelos, D. Pitman, S. Barnett, P. M. Hattersley, M. H. Lehto, P. M. Watkins, J. F. Kral, K. W. Bell, C. Y. Chang, M. F. Turner, F. Odorici, J. W. Gary, Max Weber, H. Mes, I. P. Duerdoth, R. Mir, D. Hochman, C. Sbarra, Marcello Mannelli, J. E. Duboscq, J. C. Hill, T. G. Shears, Misao Sasaki, M. Yurko, John Hobbs, Erez Etzion, Michael Dittmar, R. Lahmann, H. M. Fischer, M. J. Pearce, Horst Breuker, F. S. Merritt, G. Yekutieli, J. C. Clayton, Silvia Arcelli, Stefan Kluth, D. M. Gingrich, Shlomit Tarem, D. C. Imrie, B. C. Shen, B. Fabbro, B. Panzer-Steindel, J. G. Layter, P. W. Jeffreys, A. K. Honma, C. Moisan, P. Scharff-Hansen, M. J. Oreglia, S. Rossberg, P. Berlich, C. J. Oram, L. Köpke, G. P. Siroli, R. P. Middleton, W. G. Scott, G. Beaudoin, A. A. Carter, G. A. Beck, Christoph Schwick, Achim Stahl, J. Mildenberger, Harold Nguyen, P. Teixeira-Dias, P. E.L. Clarke, A. D. Schaile, J. Steuerer, Matthias Schröder, Gunter Wolf, Roger Jones, R. Van Kooten, P. F. Harrison, J. A. McKenna, A. M. Smith, G. Vasseur, R. Kowalewski, M. J. Losty, J. M. Lorah, D. R. Rust, Gideon Bella, H. J. Burckhart, Jacqueline Batley, H. Lafoux, N. Paz-Jaoshvili, S. Wotton, A. Michelini, J. R. Carter, G. N. Patrick, Otmar Biebel, P. D. Acton, Stephen Lloyd, A. Yeaman, G. E. Richards, D. G. Charlton, D. L. Wagner, P. Bright-Thomas, M. Tecchio, G. A. Snow, C. P. Ward, Kiyotomo Kawagoe, B. Lorazo, B. Schmitt, J. M. Roney, Andris Skuja, V. H. Winterer, A. M. Lee, M. W. Redmond, P. Igo-Kemenes, H. Jeremie, T. J. Smith, A. C. Janissen, K. Stephens, H. Deng, Margret Fincke-Keeler, N. K. Watson, J. R. McNutt, Sachio Komamiya, T. J. McMahon, R. Humbert, P. Mättig, R. Bartoldus, D. A. Hinshaw, D. L. Rees, R. Yaari, Tetsuro Mashimo, J. Goldberg, M. A. Thomson, H. O. Ogren, W. Mohr, J. Schwiening, U. Maur, B. Nellen, P. Leblanc, E. Ros, A. T. Watson, P. Weber, S. A. Robins, R. K. Carnegie, S. Bethke, Christoph Geich-Gimbel, Marco Cuffiani, A. Astbury, V. Gibson, G. Quast, J. A. Wilson, T. P. Kokott, H. G. Evans, A. Luig, U. Müller, Paul Kyberd, I. J. Bloodworth, P. Pfister, F. K. Loebinger, T. Behnke, J. Kroll, R.J. Akers, Gideon Alexander, P. S. Wells, M. J. Goodrick, Paolo Capiluppi, Norbert Wermes, W. J. Collins, Sherry Towers, John Baines, I. Cohen, T. Kawamoto, T. Hilse, A. J. Martin, P. A. Elcombe, S. W. O'Neale, F. X. Gentit, K. J. Anderson, J. E. Conboy, Randall Sobie, G. D. Lafferty, W. Schappert, O. Runolfsson, J. Banks, Ehud Duchovni, R. Shypit, S. Orito, M. Rosvick, M. Settles, A. Pouladdej, Shlomo Dado, G. Duckeck, R. Ströhmer, M. Jimack, Terry Richard Wyatt, G. T. Zorn, H. Ihssen, N. J. Tresilian, D. R. Ward, T. W. Pritchard, E. do Couto e Silva, G. Transtromer, S. W. Gensler, R. D. Heuer, A. Rollnik, R. Giacomelli, H. M. Bosch, C. K. Hargrove, Wolfram Dietrich Zeuner, M. Foucher, C. Beeston, X. C. Lou, Fabrizio Fabbri, S. J. Hillier, T. Kobayashi, M. Coupland, Claudio Grandi, C. J. Virtue, M. Morii, Peter R Hobson, P. Poffenberger, R. E. Hughes-Jones, O. Schaile, D. Axen, A. Jawahery, C. Gorn, Peter Sherwood, D. Van del Plas, J. Becker, R. W. Springer, Alexander Wagner, M. Hansroul, John Allison, G. W. Wilson, D. Karlen, J. Hagemann, J. Ludwig, Giora Mikenberg, K. Runge, J. von Krogh, P. Bock, M. Jones, C. Burgard, A. M. Rossi, T. Tsukamoto, S. Levegrün, C. M. Hawkes, G. J. VanDalen, M. Cooper, Daniel Lellouch, C. H. Shepherd-Themistocleous, Dave Robinson, R. G. Kellogg, R. J. Homer, Takehiko Mori, W. R. Gibson, L. A. del Pozo, D. S. Koetke, N. I. Geddes, Stefano Marcellini, James Letts, Claude Leroy, J. P. Pansart, B. Boden, B. Poli, C. Jui, A. Skillman, F. C. Grant, M. A. Whalley, M. Hauschild, A. Beck, A. Buijs, D. M. Strom, A. Gaidot, M. Kuwano, C. Stegmann, E. Heflin, R. M. Brown, Lorne Levinson, T. Wlodek, M. Sproston, C. Markus, H. Przysiezniak, P. Routenburg, P. Paschievici, N. Tesch, A. Dieckmann, B. W. Kennedy, M. Fierro, E. Torrente-Lujan, D. E. Plane, P. Bentkowski, G. M. Dallavalle, D. J.P. Dumas, Gregor Herten, C. Wahl, B. Wilkens, J. E. Pilcher, G. G. Hanson, G. Giacomelli, P. Schenk, M. S. Dixit, Frans Meijers, J. P. Martin, S. De Jong, J. Hart, J. D. Gillies, R. J. Barlow, D. J. Miller, F. Lamarche, R. J. Hemingway, P. Jovanovic, Austin Ball, D. Menszner, Alessandro Montanari, H. Takeda, and F. G. Oakham
Subjects: Physics, Particle physics, Muon, Physics and Astronomy (miscellaneous), Electron–positron annihilation, media_common.quotation_subject, Hadron, Asymmetry, Nuclear physics, Momentum, Engineering (miscellaneous), Energy (signal processing), Lepton, Bar (unit), media_common
Abstract: The forward-backward asymmetries of $$e^ + e^ - \to Z^0 \to b\bar b and e^ + e^ - \to Z^0 \to c\bar c$$ have been measured by the OPAL Collaboration using samples of hadronicZ 0 decays in which electron or muon candidates were observed. The asymmetries were measured simultaneously in a two parameter fit, which used the distributions of the track momentum and transverse momentum component with respect to the associated jet to distinguish lepton candidates from different sources. From a sample of 360 000 hadronic events with centre-of-mass energies within ±0.5 GeV of theZ 0 mass and mean energy 91.24. GeV, the values obtained for the $$b\bar b$$ asymmetry before and after correcting, for the effect of $$B^0 \overline {B^0 } $$ mixing, and for the $$c\bar c$$ asymmetry are, respectively: $$\begin{gathered} A_{FB}^{b,mix} = 0.070 \pm 0.014(stat) \pm 0.005(sys), \hfill \\ A_{FB}^b = 0.092 \pm 0.018(stat) \pm 0.007(sys) \hfill \\ \pm 0.003(mix), \hfill \\ A_{FB}^c = 0.014 \pm 0.030(stat) \pm 0.020(sys). \hfill \\ \end{gathered} $$ The measurement of the $$b\bar b$$ asymmetry is confirmed by a measurement using only leptons with high transverse momentum. This sample is highly enriched in semileptonic decays ofb hadrons. Measurements using high transverse momentum leptons were also performed using samples of events with centre-of-mass energies further from theZ 0 mass. After correcting for the effect of $$B^0 \overline {B^0 } $$ mixing, the results are: $$\begin{gathered} A_{FB}^b (\langle \sqrt s \rangle = 89.66GeV) \hfill \\ = 0.071 \pm 0.054(stat) \pm 0.007(sys) \pm 0.002(mix), \hfill \\ A_{FB}^b (\langle \sqrt s \rangle = 92.75GeV) \hfill \\ = 0.131 \pm 0.047(stat) \pm 0.012(sys) \pm 0.004(mix). \hfill \\ \end{gathered} $$
Published: 1993

26. A modular electronic readout system for the OPAL electromagnetic presampler

Author: K. J. Anderson, D. Strom, M. J. Oreglia, S. W. Gensler, M. W. Redmond, H.H. Nguyen, F. S. Merritt, J.M. Roney, W. Schappert, H. Sanders, J. Kroll, J. E. Pilcher, and J.D. Hobbs
Subjects: Physics, Nuclear and High Energy Physics, Analogue electronics, business.industry, Dynamic range, Detector, Dead time, Signal, Particle detector, Programmable logic device, business, Instrumentation, Computer hardware, Electronic circuit
Abstract: The readout system used to sample and digitize the 21 504 channels of the OPAL electromagnetic barrel presampler is described. The system consists of semi-custom analog electronics mounted directly on the detector to provide integrate-and-hold capability and custom VME boards to implement the digitization functions. The data from one event is digitized completely in under 7 ms. This meets the OPAL requirement of a sustained 10 Hz trigger rate with less than 10% dead time. A minimum ionizing particle deposits 2.7 pC in a single layer of the presampler, and the largest signal commonly seen in 200 pC. The dynamic range of the readout system is 0.032 to 1000 pC. The noise on a single channel is typically 0.2 pC. A linear analog calibration is automatically applied on a channel-by-channel basis. Programmable logic is used extensively.
Published: 1993

27. Inclusive neutral vector meson production in hadronicZ 0 decays

Author: P. Igo-Kemenes, C. Moisan, J. P. Walker, J. Goldberg, P. Teixeira-Dias, G. Maringer, B. Nellen, H. Jeremie, R. E. Hughes-Jones, U. Maur, M. Hauschild, P. M. Hattersley, R. Mir, P. Leblanc, V. Gibson, J. M. Lorah, I. J. Bloodworth, D. C. Imrie, Kiyotomo Kawagoe, C. Markus, P. Paschievici, Sachio Komamiya, G. P. Siroli, Christoph Schwick, J. M. Roney, D. A. Hinshaw, P. Weber, E. Ros, H. Mes, I. P. Duerdoth, S. Schreiber, A. Astbury, T. J. McMahon, D. J. Miller, W. Mohr, B. C. Shen, H. G. Evans, E. do Couto e Silva, P. E.L. Clarke, M. J. Goodrick, I. Cohen, M. Jimack, M. Hansroul, M. Yurko, M. J. Oreglia, R. Van Kooten, P. W. Jeffreys, D. Pitman, T. P. Kokott, Carla Sbarra, John Allison, O. Ganel, A. J. Martin, J. Schwiening, R. K. Carnegie, A. K. Honma, W. G. Scott, J. Steuerer, F. G. Oakham, M. Settles, P. S. Wells, R. G. Kellogg, J. G. Layter, A. M. Lee, M. Jobes, U. Binder, A. D. Schaile, C. H. Shepherd-Themistocleous, M. F. Turner, T. Behnke, P. Scharff-Hansen, M. H. Lehto, M. Foucher, P. A. Elcombe, R. J. Homer, R. Kowalewski, Terry Richard Wyatt, J. C. Clayton, Stefano Marcellini, J. A. Wilson, James Letts, Margret Fincke-Keeler, M. Coupland, G. A. Snow, C. P. Ward, D. L. Rees, J. Becker, T. Mouthuy, G. N. Patrick, F. S. Merritt, Paul Kyberd, O. Schaile, G. W. Wilson, S. Wotton, W. Schappert, F. K. Loebinger, D. Axen, A. Jawahery, M. J. Losty, A. Skuja, D. Karlen, A. Simon, Otmar Biebel, J. Hart, A. M. Smith, V. H. Winterer, M. W. Redmond, G. T. Zorn, G. Tysarczyk-Niemeyer, G. E. Richards, D. G. Charlton, D. L. Wagner, R. Yaari, G. Vasseur, P. Pfister, C. M. Hawkes, M. Cooper, Daniel Lellouch, S. Bethke, Marco Cuffiani, P. Poffenberger, Richard Keeler, G. Beaudoin, J. D. Gillies, J. P. Martin, C. K. Hargrove, M. Manelli, H. Deng, R. Humbert, Peter Sherwood, B. Lorazo, R. W. Springer, Alexander Wagner, A. Rollnik, A. M. Rossi, P. Berlich, L. Köpke, Takehiko Mori, R. J. Barlow, M. Morii, Michael Dittmar, J. Hagemann, J. Ludwig, H. Przysiezniak, G. J. Van Dalen, G. Yekutieli, K. Runge, P. Bock, S. De Jong, Peter R Hobson, D. R. Rust, Tetsuro Mashimo, T. Tsukamoto, P. Lennert, S. Levegrün, A. Gaidot, M. Kuwano, T. Wlodek, K. Stephens, Claude Leroy, Tohru Takeshita, Shlomo Dado, J. R. McNutt, M. Sproston, J. P. Pansart, T. Kawamoto, J. A. McKenna, F. Lamarche, F. Odorici, N. Paz-Jaoshvili, C. Wahl, W. J. Collins, Erez Etzion, P. Routenburg, F. C. Grant, M. A. Whalley, R. J. Hemingway, A. A. Carter, Randall Sobie, G. D. Lafferty, J. Mildenberger, N. Tesch, A. Dieckmann, C. P. Howarth, T. Hilse, Harold Nguyen, X. C. Lou, S. Orito, Stefan Kluth, M. Rosvick, Shlomit Tarem, P. Jovanovic, R. F. McGowan, Austin Ball, O. Runolfsson, D. Menszner, G. Duckeck, R. Ströhmer, Georges Azuelos, J. E. Pilcher, G. Quast, John Baines, A. Buijs, D. M. Strom, S. Rossberg, W. Gorn, Alessandro Montanari, John Hobbs, Giora Mikenberg, H. O. Ogren, Claudio Grandi, C. J. Oram, G. A. Bahan, Tara Shears, J. F. Kral, K. W. Bell, S. W. O'Neale, D. R. Ward, C. Y. Chang, G. Transtromer, T. W. Pritchard, H. M. Bosch, R. P. Middleton, Christoph Geich-Gimbel, Max Weber, T. J. Smith, A. Yeaman, N. K. Watson, J. Banks, Wolfram Dietrich Zeuner, G. G. Hanson, N. J. Tresilian, P. Taras, J. C. Hill, Misao Sasaki, S. Weisz, R. D. Heuer, Mitsuaki Nozaki, D. G. Fong, Fabrizio Fabbri, P. Mättig, J. Kroll, Horst Breuker, D. Van den plas, J. Gascon, S. Barnett, G. Giacomelli, H. von der Schmitt, N. J. Thackray, E.J. Prebys, F. X. Gentit, J. von Krogh, J. E. Conboy, J. W. Gary, M. S. Dixit, Frans Meijers, J. E. Duboscq, Dave Robinson, L. A. del Pozo, A. Pouladdej, K. J. Anderson, C. Jui, N. I. Geddes, B. Boden, B. Poli, H. M. Fischer, A. Michelini, A. C. Janissen, J. R. Carter, D. Hochmann, Silvia Arcelli, Phillip Allport, P. Singh, Gideon Alexander, Paolo Capiluppi, P. Schenk, R. W. L. Jones, N. Wermes, Ehud Duchovni, R. Shypit, P. Le Du, B. Panzer-Steindel, H. Ihssen, S. W. Gensler, T. Kobayashi, C. J. Virtue, P. G. Estabrooks, Gideon Bella, H. J. Burckhart, Jacqueline Batley, P. M. Watkins, P. F. Harrison, P. D. Acton, Stephen Lloyd, M. Tecchio, D. E. Plane, Stephen Hillier, G. M. Dallavalle, Alan Watson, D. J.P. Dumas, S. Bougerolle, W. R. Gibson, A. Beck, E. Heflin, R. M. Brown, Lorne Levinson, and B. W. Kennedy
Subjects: Physics, Particle physics, Meson production, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Hadron, Monte Carlo method, Nuclear physics, Pion, Mass spectrum, High Energy Physics::Experiment, Neutral vector, Ionization energy, Engineering (miscellaneous), Particle Physics - Experiment
Abstract: Results are reported of a study of neutral vector meson production in multihadronicZ0 decays in the OPAL experiment at LEP. Pions and kaons have been identified by specific ionisation energy loss andK±π∓ andK+K− mass spectra have been fitted, in bins of the scaled momentum variablexp, to combinations of resonance signals and non-resonant backgrounds. Rates are given forK*(892)° and o(1020), and production cross sections are compared to the predictions of Monte Carlo models. Overall multiplicities have been determined as 0.76±0.07±0.06K*(892)° and 0.086±0.015±0.010 o(1020) per hadronicZ0 decay (the quoted errors are respectively statistical and systematic). Momentum dependent distortions of the ππ mass spectra, possibly associated indirectly with Bose-Einstein effects, have prevented reliable measurement of the ρ(770)° cross section in this study.
Published: 1992

28. A study of charged particle multiplicities in hadronic decays of theZ 0

Author: W. R. Gibson, C. Ho, R. Mir, H. Mes, A. Beck, H. Oh, E. Heflin, Margret Fincke-Keeler, I. P. Duerdoth, R. M. Brown, Lorne Levinson, B. W. Kennedy, K. J. Anderson, S. Bougerolle, F. Lamarche, R. J. Hemingway, D. E. Plane, Stephen Hillier, G. M. Dallavalle, Alan Watson, D. J.P. Dumas, M. Jobes, K. Stephens, J. R. McNutt, N. C. Wood, M. Jimack, John Allison, J. Goldberg, P. Jovanovic, Austin Ball, D. Menszner, F. Odorici, U. Binder, G. A. Snow, C. P. Ward, P. Pfister, J. P. Martin, M. W. Moss, P. M. Hattersley, M. J. Oreglia, J. R. Carter, G. N. Patrick, Silvia Arcelli, C. Fukunaga, P. Scharff-Hansen, W. J. Larson, R. G. Kellogg, B. Holl, I. Zacharov, Horst Breuker, B. Nellen, Alessandro Montanari, P. A. Elcombe, D. J. Miller, O. Runolfsson, V. Gibson, G. Quast, S. De Jong, John Baines, P. Leblanc, A. Astbury, D. C. Imrie, S. Wotton, Phillip Allport, G. Beaudoin, John Hobbs, Stefano Marcellini, J. Banks, P. Igo-Kemenes, T. Mouthuy, A. M. Smith, O. Ganel, James Letts, M. Weymann, G. Maringer, H. Jeremie, A. J. Martin, J. L. Pinfold, Tohru Takeshita, R. E. Hughes-Jones, U. Maur, A. Simon, G. P. Siroli, P. S. Wells, M. Hauschild, D. R. Ward, Shlomo Dado, G. Vasseur, D. L. Rees, B. Lorazo, M. Hansroul, H. E. Stier, Claudio Grandi, F. S. Merritt, K. Riles, G. Transtromer, J. Becker, P. G. Estabrooks, G. T. Zorn, A. M. Rossi, S. Levegrün, M. Yurko, S. Weisz, R. D. Heuer, Fabrizio Fabbri, M. J. Goodrick, Otmar Biebel, D. G. Charlton, P. Paschievici, C. J. Virtue, Terry Richard Wyatt, M. Coupland, P. Debu, I. Cohen, J. Mildenberger, Harold Nguyen, N. K. Watson, B. B. Brabson, P. W. Jeffreys, D. Van den plas, C. K. Hargrove, X. C. Lou, Gideon Alexander, N. I. Geddes, P. E.L. Clarke, D. G. Fong, M. Couch, Richard Keeler, Paolo Capiluppi, P. Schenk, A. M. Lee, B. Boden, J. Gascon, Georges Azuelos, P. M. Watkins, B. Poli, H. von der Schmitt, H. Takeda, Claude Leroy, G. Eckerlin, Giora Mikenberg, J. P. Pansart, G. J. VanDalen, J. von Krogh, D. R. Rust, N. Wermes, H. M. Fischer, A. Michelini, F. C. Grant, J. A. McKenna, R. Humbert, M. A. Whalley, B. P. O'Neill, J. F. Kral, F. G. Oakham, A. C. Janissen, K. W. Bell, J. W. Gary, R. J. Homer, Ehud Duchovni, R. Shypit, P. Lennert, Max Weber, I. Wingerter, Marcello Mannelli, S. A. Robins, R. F. McGowan, D. E. Klem, P. Ashton, A. Buijs, Andris Skuja, J. C. Hill, H. Ihssen, H. O. Ogren, Dave Robinson, M. F. Turner, Christoph Geich-Gimbel, Kiyotomo Kawagoe, Misao Sasaki, B. C. Shen, Gideon Bella, Tetsuro Mashimo, P. Poffenberger, S. W. O'Neale, Peter R Hobson, S. W. Gensler, J. D. Gillies, Paul Kyberd, F. K. Loebinger, L. A. del Pozo, A. K. Honma, M. M. Deninno, W. G. Scott, J. Kroll, C. Moisan, H. J. Burckhart, O. Schaile, J. P. Walker, R. Yaari, T. Kobayashi, Jacqueline Batley, R. Van Kooten, D. Pitman, F. X. Gentit, Sachio Komamiya, T. Kawamoto, J. E. Conboy, M. H. Lehto, E. Ros, S. Bethke, Michael Dittmar, M. Ogg, R. Kowalewski, P. Teixeira-Dias, R. J. Barlow, W. Gorn, M. W. Redmond, Marco Cuffiani, G. Yekutieli, J. M. Roney, A. Pouladdej, W. J. Collins, Randall Sobie, S. Orito, M. Rosvick, G. A. Bahan, A. Rollnik, G. G. Hanson, A. A. Carter, A. Gaidot, D. Hochman, N. J. Thackray, G. D. Lafferty, M. Kuwano, P. Weber, T. P. Kokott, Rene Brun, M. J. Losty, J. Hart, M. Sproston, S. J. Pawley, C. Y. Chang, P. Berlich, Claus Kleinwort, L. Köpke, T. W. Pritchard, H. Tsukamoto, P. Routenburg, P. Taras, Mitsuaki Nozaki, C. Wahl, S. Schreiber, G. Giacomelli, Y. Yang, T. J. McMahon, A. Dieckmann, J. Schwiening, C. P. Howarth, P. F. Harrison, P. Singh, R. K. Carnegie, H. Przysiezniak, J. E. Pilcher, J. A. Wilson, P. D. Acton, Stephen Lloyd, R. W. L. Jones, E.J. Prebys, A. D. Schaile, W. Schappert, P. Le Du, H. Kreutzmann, B. Panzer-Steindel, M. S. Dixit, Frans Meijers, V. H. Winterer, S. R. Hou, J. M. Lorah, W. Mohr, J. G. Layter, G. Duckeck, R. Ströhmer, D. Strom, S. Sanghera, H. M. Bosch, Wolfram Dietrich Zeuner, D. A. Hinshaw, T. Behnke, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, R. W. Springer, Alexander Wagner, J. Hagemann, J. Ludwig, K. Runge, P. Bock, I. J. Bloodworth, M. Settles, G. W. Wilson, D. Karlen, T. J. Smith, P. Mättig, C. M. Hawkes, M. Cooper, Daniel Lellouch, Takehiko Mori, Erez Etzion, Gareth J. Barker, Shlomit Tarem, S. Rossberg, C. J. Oram, and R. P. Middleton
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Hadron, Multiplicity (mathematics), Charged particle, Sphericity, Nuclear physics, Log-normal distribution, Gamma distribution, High Energy Physics::Experiment, Parton shower, Engineering (miscellaneous)
Abstract: We present an analysis of multiplicity distributions of charged particles produced inZ 0 hadronic decays. The results are based on the analysis of 82941 events collected within 100 MeV of theZ 0 peak energy with the OPAL detector at LEP. The charged particle multiplicity distribution, corrected for initial-state radiation and for detector acceptance and resolution, was found to have a mean 〈n ch〉=21.40±0.02(stat.)±0.43(syst.) and a dispersionD=6.49±0.02(stat.)±0.20(syst.). The shape is well described by the Lognormal and Gamma distributions. A negative binomial parameterisation was found to describe the shape of the multiplicity distribution less well. A comparison with results obtained at lower energies confirms the validity of KNO(-G) scaling up to LEP energies. A separate analysis of events with low sphericity, typically associated with two-jet final states, shows the presence of features expected for models based on a stochastic production mechanism for particles. In all cases, the features observed in the data are well described by the Lund parton shower model JETSET.
Published: 1992

29. A measurement of strange baryon production in hadronic Z0 decays

Author: P. Paschievici, D. Karlen, A. Dieckmann, R. Mir, G. P. Siroli, A. Astbury, R. Van Kooten, C. H. Shepherd-Themistocleous, M. Hansroul, T. W. Pritchard, A. Wagner, John Hill, Silvia Arcelli, B. Boden, D. Menszner, T. Mouthuy, Gideon Bella, G. Vasseur, S. De Jong, J. C. Clayton, H. J. Burckhart, Jacqueline Batley, C. Geich-Gimbel, S. Rossberg, D. J. Miller, R. K. Carnegie, P. S. Wells, P. E.L. Clarke, Terry Richard Wyatt, F. G. Oakham, G. T. Zorn, T. Hilse, L. Levinson, R. J. Homer, Kiyotomo Kawagoe, A. Beck, H. G. Evans, John Hobbs, Tohru Takeshita, M. Fincke-Keeler, M. J. Oreglia, F. C. Grant, T. Wlodek, M. A. Whalley, A. M. Rossi, T. Tsukamoto, P. Schenk, M. J. Goodrick, N. Tesch, A. K. Honma, F. S. Merritt, R. Humbert, C. J. Virtue, Sachio Komamiya, W. Mohr, A. Buijs, D. M. Strom, G. N. Patrick, J. Mildenberger, C. Schwick, Richard Keeler, D. Hochman, J. P. Martin, P. Routenburg, O. Ganel, E. Ros, J. P. Walker, K. Runge, M. J. Losty, A. C. Janissen, C. J. Oram, U. Binder, J. M. Roney, J. R. Carter, A. Simon, M. Cooper, A. Rollnik, P. Singh, J. F. Kral, G. Beaudoin, J. A. McKenna, N. Wermes, P. Pfister, B. Poli, R. M. Brown, P. W. Jeffreys, J. Hart, J. Becker, K. J. Anderson, P. Weber, A. J. Martin, Carla Sbarra, X. C. Lou, A. A. Carter, T. P. Kokott, K. Stephens, R. F. McGowan, A. Yeaman, G. E. Richards, C. K. Hargrove, T. Behnke, Misao Sasaki, E. Heflin, J. P. Pansart, A. Michelini, D. A. Hinshaw, C. Markus, Marco Cuffiani, H. O. Ogren, D. G. Charlton, D. L. Wagner, D. Lellouch, C. Y. Chang, I. J. Bloodworth, C. Moisan, P. Berlich, B. C. Shen, G. Tysarczyk-Niemeyer, P. M. Watkins, P. Igo-Kemenes, H. Deng, Harold Nguyen, H. Ihssen, P. Bock, V. Gibson, Mitsuaki Nozaki, R. E. Hughes-Jones, J. G. Layter, A. Gaidot, James D Gillies, S. Wotton, Stefan Kluth, D. J.P. Dumas, R. Kowalewski, J. Kroll, P. Le Du, John Baines, S. Schreiber, S. Bethke, J. Schwiening, B. W. Kennedy, Tara Shears, F. X. Gentit, N. I. Geddes, V. H. Winterer, J. E. Conboy, Richard J Hemingway, B. Panzer-Steindel, M. Settles, G. Duckeck, M. Coupland, P. D. Acton, M. Morii, T. Kawamoto, S. W. O'Neale, Peter R Hobson, H. Mes, O. Runolfsson, P. Lennert, U. Maur, M. Foucher, R. J. Barlow, C. Jui, D. Pitman, Horst Breuker, P. M. Hattersley, P. Poffenberger, S. Orito, C. Wahl, E. do Couto e Silva, P. Mättig, D. R. Ward, P. Teixeira-Dias, M. F. Turner, G. A. Snow, C. P. Ward, G. W. Wilson, M. Hauschild, I. P. Duerdoth, F. Lamarche, H. M. Bosch, D. C. Imrie, C. Leroy, J. Steuerer, G. G. Hanson, G. Alexander, S. Bougerolle, J. Hagemann, H. Przysiezniak, E. Etzion, B. Lorazo, G. Quast, P. Leblanc, G. Giacomelli, J. Goldberg, Wolfram Dietrich Zeuner, E.J. Prebys, R. Ströhmer, Claudio Grandi, T. J. Smith, W. J. Collins, S. Dado, N. K. Watson, F. K. Loebinger, G. D. Lafferty, D. Axen, Frans Meijers, J. M. Lorah, A. Jawahery, B. Nellen, D. E. Plane, C. M. Hawkes, Peter Sherwood, W. R. Gibson, Stephen Hillier, G. M. Dallavalle, R. W. Springer, A. M. Lee, Takehiko Mori, J. R. McNutt, K. W. Bell, R. P. Middleton, M. Weber, J. Ludwig, C. P. Howarth, M. W. Redmond, A. Pouladdej, J. Gascon, Alan Watson, P. G. Estabrooks, J. E. Pilcher, G. Mikenberg, G. Maringer, S. Barnett, R. Yaari, S. Tarem, O. Biebel, M. Jimack, N. J. Thackray, John Allison, A. D. Schaile, P. Jovanovic, P. A. Elcombe, R. G. Kellogg, Austin Ball, W. Schappert, F. Odorici, Stefano Marcellini, Alessandro Montanari, James Letts, D. L. Rees, G. J. VanDalen, N. Paz-Jaoshvili, M. Kuwano, G. Transtromer, W. G. Scott, P. F. Harrison, Stephen Lloyd, M. Tecchio, M. Yurko, R. Shypit, S. W. Gensler, T. Kobayashi, D. G. Fong, H. von der Schmitt, Phillip Allport, R. Sobie, H. Jeremie, J. W. Gary, Marcello Mannelli, J. E. Duboscq, M. Jobes, P. Kyberd, Paolo Capiluppi, P. Scharff-Hansen, A. M. Smith, Andris Skuja, Tetsuro Mashimo, W. Gorn, G. Yekutieli, M. Rosvick, G. A. Bahan, R. W.L. Jones, J. von Krogh, Dave Robinson, L. A. del Pozo, Michael Dittmar, H. M. Fischer, T. J. McMahon, O. Schaile, M. H. Lehto, E. Duchovni, J. A. Wilson, S. Levegrün, L. Köpke, I. Cohen, M. S. Dixit, J. Banks, G. Azuelos, N. J. Tresilian, S. Weisz, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, D. R. Rust, M. Sproston, and P. Taras
Subjects: Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Octet, High Energy Physics::Lattice, Electron–positron annihilation, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, OPAL detector, Baryon, Nuclear physics, Momentum, Diquark, QCD predictions, High Energy Physics::Experiment, Strange baryons, Particle Physics - Experiment, Spin-½
Abstract: The production of the octet and decuplet baryons Λ, Ξ − , Σ (1385) ± , Ξ(1530) 0 and Ω − and the corresponding antibaryons has been measured in a sample of 485 000 hadronic Z 0 decays. Results on differential and integrated cross sections are presented. The differential cross section of Λ baryons is found to be softer than the one predicted by the Jetset and Herwig Monte Carlo generators. The measured decuplet yields are found to disagree with the simple diquark picture where only one tuning parameter for spin 1 diquarks is used. Comparisons of the momentum spectra for Λ and Ξ − with the predictions of an analytical QCD formula are also presented.
Published: 1992

30. A study of two-particle momentum correlations in hadronic Z0 decays

Author: M. Jimack, P. Igo-Kemenes, G. Maringer, Shlomo Dado, John Allison, H. Jeremie, D. J. Miller, F. Lamarche, R. J. Hemingway, D. E. Klem, Michael Dittmar, G. Yekutieli, P. S. Wells, A. A. Carter, R. E. Hughes-Jones, U. Maur, Terry Richard Wyatt, I. J. Bloodworth, X. C. Lou, R. G. Kellogg, P. Jovanovic, Horst Breuker, Erez Etzion, H. Mes, M. Coupland, Austin Ball, D. Menszner, F. C. Grant, P. G. Estabrooks, D. R. Rust, R. Mir, I. P. Duerdoth, M. A. Whalley, Stefano Marcellini, Gareth J. Barker, M. Settles, B. C. Shen, K. J. Anderson, Gideon Bella, Giora Mikenberg, Shlomit Tarem, P. E.L. Clarke, H. Oh, E. do Couto e Silva, Alessandro Montanari, James Letts, W. J. Collins, K. Stephens, J. Steuerer, A. K. Honma, P. Lennert, H. J. Burckhart, Randall Sobie, G. D. Lafferty, S. Rossberg, W. G. Scott, A. Buijs, C. Y. Chang, Jacqueline Batley, C. J. Oram, P. M. Watkins, H. O. Ogren, J. R. McNutt, M. Yurko, P. M. Hattersley, W. R. Gibson, P. Taras, Christoph Geich-Gimbel, T. W. Pritchard, G. W. Wilson, R. P. Middleton, N. I. Geddes, R. Kowalewski, J. Mildenberger, Harold Nguyen, D. Karlen, M. Hauschild, Glenn Patrick, P. W. Jeffreys, A. M. Lee, E. Ros, M. J. Oreglia, P. Paschievici, Kiyotomo Kawagoe, M. Hansroul, H. Takeda, M. M. Deninno, J. Goldberg, B. Boden, D. Axen, M. J. Losty, B. Nellen, F. G. Oakham, G. A. Snow, C. P. Ward, Silvia Arcelli, A. Jawahery, J. Kroll, B. Poli, N. Paz-Jaoshvili, P. Leblanc, J. M. Roney, Paul Kyberd, F. K. Loebinger, A. Beck, P. F. Harrison, T. J. Smith, J. Hart, F. X. Gentit, E. Heflin, G. Tysarczyk-Niemeyer, Richard Keeler, R. Yaari, J. E. Conboy, P. Weber, M. F. Turner, S. Bethke, A. D. Schaile, V. Gibson, Peter Sherwood, J. R. Carter, P. Poffenberger, G. Quast, M. Ogg, P. D. Acton, Stephen Lloyd, M. W. Redmond, Marco Cuffiani, H. G. Evans, J. Banks, J. P. Pansart, P. Mättig, R. M. Brown, Lorne Levinson, J. D. Gillies, A. Rollnik, A. Simon, D. G. Fong, Otmar Biebel, G. E. Richards, M. J. Goodrick, I. Cohen, N. J. Tresilian, J. G. Layter, John Baines, N. Wermes, A. Pouladdej, R. W. Springer, Alexander Wagner, Tohru Takeshita, V. H. Winterer, T. Mouthuy, S. Weisz, R. D. Heuer, D. G. Charlton, D. L. Wagner, J. Gascon, C. M. Hawkes, H. von der Schmitt, M. Cooper, P. Singh, Claude Leroy, B. W. Kennedy, Fabrizio Fabbri, M. Couch, Ehud Duchovni, R. Shypit, Daniel Lellouch, J. Hagemann, D. Van den plas, J. Ludwig, R. J. Barlow, D. C. Imrie, K. Runge, P. Bock, Takehiko Mori, S. R. Hou, C. Wahl, A. Astbury, T. P. Kokott, Rene Brun, Carla Sbarra, F. S. Merritt, H. Ihssen, R. J. Homer, R. Van Kooten, Georges Azuelos, D. Pitman, R. W. L. Jones, D. R. Ward, R. Humbert, M. H. Lehto, G. Transtromer, C. P. Howarth, S. W. Gensler, J. F. Kral, G. P. Siroli, K. W. Bell, P. Le Du, D. A. Hinshaw, Christoph Schwick, S. Wotton, T. Kobayashi, C. J. Virtue, Max Weber, C. Fukunaga, B. Panzer-Steindel, O. Ganel, J. E. Pilcher, S. Bougerolle, John Hobbs, Misao Sasaki, J. A. McKenna, A. M. Rossi, F. Odorici, T. Tsukamoto, T. Behnke, Phillip Allport, S. Sanghera, S. Levegrün, H. M. Fischer, R. F. McGowan, A. J. Martin, A. Michelini, A. C. Janissen, J. W. Gary, C. Moisan, J. P. Walker, G. Duckeck, R. Ströhmer, S. A. Robins, O. Runolfsson, D. Strom, P. Teixeira-Dias, D. E. Plane, G. T. Zorn, Marcello Mannelli, J. E. Duboscq, Stephen Hillier, P. Berlich, L. Köpke, H. M. Bosch, Wolfram Dietrich Zeuner, G. M. Dallavalle, K. Riles, Andris Skuja, J. P. Martin, T. Kawamoto, Gideon Alexander, Paolo Capiluppi, P. Schenk, S. Barnett, Alan Watson, D. J.P. Dumas, D. Hochman, N. J. Thackray, John Hill, Tetsuro Mashimo, C. K. Hargrove, S. De Jong, S. Orito, Claudio Grandi, M. Rosvick, W. Gorn, Margret Fincke-Keeler, G. A. Bahan, M. Jobes, U. Binder, P. Scharff-Hansen, H. Przysiezniak, P. Pfister, G. G. Hanson, A. M. Smith, G. Vasseur, B. Lorazo, G. Giacomelli, N. K. Watson, E.J. Prebys, M. S. Dixit, S. Komamiya, Frans Meijers, S. W. O'Neale, Peter R Hobson, J. M. Lorah, W. Mohr, A. Gaidot, M. Kuwano, T. Wlodek, M. Sproston, P. Routenburg, N. Tesch, A. Dieckmann, P. A. Elcombe, D. L. Rees, J. Becker, G. J. VanDalen, S. Schreiber, T. J. McMahon, J. Schwiening, R. K. Carnegie, J. A. Wilson, W. Schappert, J. von Krogh, Dave Robinson, L. A. del Pozo, and G. Beaudoin
Subjects: Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, Logarithm, High Energy Physics::Phenomenology, Monte Carlo method, Hadron, String (physics), Hadronization, Nuclear physics, Momentum, High Energy Physics::Experiment, Parton shower, Particle Physics - Experiment
Abstract: We report on a measurement of two-particle momentum correlations in hadronic decays of the Z 0 at LEP. These data are compared with recent analytic QCD calculations based on the summation of leading and next-to-leading logarithms, and with QCD Monte Carlo simulations. We find that the analytic calculations show the same general features as the data, but that the overall level of the correlations is not reproduced, suggesting that higher order or hadronization effects are significant. This contrasts with the success of similar QCD calculations in describing single-particle momentum distributions. QCD Monte Carlo models are found to give a reasonable level of correlation, with parton shower models incorporating string hadronization giving the best description of the data.
Published: 1992

31. A measurement of electron production in hadronicZ 0 decays and a determination of $$\Gamma (Z^0 \to b\bar b)$$

Author: A. Simon, Otmar Biebel, D. G. Charlton, D. L. Wagner, M. Couch, M. Hansroul, P. G. Estabrooks, R. K. Keeler, R. Humbert, Gideon Bella, H. J. Burckhart, D. Hochman, N. J. Thackray, J. Goldberg, Jacqueline Batley, A. Gaidot, B. Nellen, R. J. Homer, P. M. Watkins, P. Leblanc, P. E.L. Clarke, M. Kuwano, T. Wlodek, M. Sproston, W. J. Collins, Randall Sobie, T. Kawamoto, G. D. Lafferty, P. Routenburg, H. G. Evans, T. W. Pritchard, A. Dieckmann, T. Mouthuy, I. Wingerter, M. J. Goodrick, I. Cohen, A. Astbury, S. Orito, M. Rosvick, C. Fukunaga, S. Bougerolle, J. Hart, A. D. Schaile, C. Moisan, J. P. Walker, O. Ganel, A. J. Martin, Silvia Arcelli, V. H. Winterer, J. M. Lorah, Sachio Komamiya, P. Igo-Kemenes, G. Maringer, P. Teixeira-Dias, W. Mohr, A. M. Rossi, S. R. Hou, K. Riles, R. Mir, H. Jeremie, H. Oh, T. Tsukamoto, S. Levegrün, D. E. Klem, R. E. Hughes-Jones, U. Maur, J. von Krogh, W. R. Gibson, C. Ho, B. P. O'Neill, E. Ros, A. T. Watson, C. K. Hargrove, R. Yaari, R. Van Kooten, S. Wotton, P. Singh, Y. Yang, Margret Fincke-Keeler, P. Ashton, N. I. Geddes, A. Beck, S. Bethke, Marco Cuffiani, D. Pitman, P. A. Elcombe, E. Heflin, M. J. Oreglia, Dave Robinson, R. M. Brown, M. I. Losty, Lorne Levinson, P. F. Harrison, R. W. L. Jones, B. Boden, L. A. del Pozo, M. F. Turner, H. Mes, B. Poli, M. H. Lehto, P. Poffenberger, P. Pfister, P. D. Acton, Stephen Lloyd, K. Stephens, B. B. Brabson, J. R. McNutt, Horst Breuker, B. W. Kennedy, T. P. Kokott, Rene Brun, D. L. Rees, J. Becker, J. R. Carter, P. Le Du, H. Kreutzmann, B. Panzer-Steindel, D. G. Fong, B. C. Shen, J. Gascon, H. von der Schmitt, Erez Etzion, Phillip Allport, G. J. VanDalen, G. N. Patrick, Michael Dittmar, G. Yekutieli, I. P. Duerdoth, Gareth J. Barker, V. Gibson, G. Quast, Shlomit Tarem, H. M. Fischer, A. Michelini, A. C. Janissen, John Baines, D. E. Plane, S. Rossberg, C. J. Oram, A. K. Honma, A. A. Carter, Stephen Hillier, G. M. Dallavalle, S. A. Robins, R. P. Middleton, D. R. Ward, M. W. Moss, G. Transtromer, W. G. Scott, D. J.P. Dumas, Gideon Alexander, Paolo Capiluppi, P. Schenk, J. W. Gary, P. M. Hattersley, S. J. Pawley, Marcello Mannelli, S. Schreiber, Andris Skuja, C. Wahl, P. Berlich, L. Köpke, T. J. McMahon, C. Y. Chang, D. R. Rust, J. Schwiening, R. K. Carnegie, John Hobbs, N. Wermes, C. P. Howarth, Ehud Duchovni, R. Shypit, S. W. O'Neale, Peter R Hobson, P. Taras, R. Kowalewski, Tetsuro Mashimo, J. A. Wilson, P. Lennert, H. Ihssen, G. Beaudoin, W. Schappert, S. W. Gensler, E. do Conto el Silva, T. Kobayashi, W. Gorn, Shlomo Dado, J. E. Pilcher, H. Takeda, F. Odirici, J. Banks, S. Weisz, R. D. Heuer, N. K. Watson, Fabrizio Fabbri, D. Van den plas, F. G. Oakham, G. A. Bahan, M. Jobes, U. Binder, Claude Leroy, P. Scharff-Hansen, W. J. Larson, D. C. Imrie, M. Hauschild, F. Lamarche, G. P. Siroli, R. J. Hemingway, J. P. Pansart, X. C. Lou, P. Paschievici, A. M. Smith, G. Vasseur, B. Lorazo, P. Jovanovic, Austin Ball, Tohru Takeshita, D. Menszner, Alessandro Montanari, Giora Mikenberg, Kiyotomo Kawagoe, Georges Azuelos, J. F. Kral, K. J. Anderson, K. W. Bell, J. D. Gillies, P. S. Wells, C. J. Virtue, R. J. Barlow, Max Weber, Terry Richard Wyatt, J. M. Roney, P. Weber, D. J. Miller, J. C. Hill, Misao Sasaki, O. Schaile, M. Coupland, F. C. Grant, M. A. Whalley, N. C. Wood, A. Buijs, G. A. Snow, C. P. Ward, G. Duckeck, R. Ströhmer, D. Strom, G. T. Zorn, H. M. Bosch, Wolfram Dietrich Zeuner, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, R. W. Springer, Alexander Wagner, J. Hagemann, J. Ludwig, K. Runge, P. Bock, C. M. Hawkes, M. Cooper, Daniel Lellouch, D. A. Hinshaw, T. Behnke, Takehiko Mori, M. Yurko, P. W. Jeffreys, A. M. Lee, T. J. Smith, O. Runolfsson, P. Mättig, Claudio Grandi, I. J. Bloodworth, M. Settles, H. Przysiezniak, G. W. Wilson, D. Karlen, F. S. Merritt, J. A. McKenna, R. F. McGowan, H. O. Ogren, Christoph Geich-Gimbel, M. M. Deninno, J. Kroll, F. X. Gentit, J. E. Conboy, M. Ogg, J. Mildenberger, Harold Nguyen, A. Pouladdej, Paul Kyberd, F. K. Loebinger, M. W. Redmond, A. Rollnik, M. Jimack, John Allison, R. G. Kellogg, Stefano Marcellini, James Letts, G. G. Hanson, G. Giacomelli, E.J. Prebys, M. S. Dixit, Frans Meijers, J. G. Layter, S. Sanghera, J. P. Martin, S. De Jong, and P. Debu
Subjects: Physics, Quark, Semileptonic decay, Particle physics, Physics and Astronomy (miscellaneous), Branching fraction, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Electron, Nuclear physics, Transverse plane, High Energy Physics::Experiment, Nuclear Experiment, Engineering (miscellaneous), Production rate
Abstract: The production rate of electrons with momentump>4 GeV/c and large momentum transverse to the jet containing the electron has been measured in 136000 hadronic decays of theZ 0 recorded with the OPAL detector at LEP in 1990. The dominant source of these electrons is the semileptonic decay of hadrons containingb quarks. If we assume that the semileptonic branching fraction ofb hadrons produced on theZ 0 resonance is the same as the branching fraction measured at the ϒ(4S) resonance, we determine $$\Gamma _{b\bar b} = 394 \pm 13 \pm 32$$ MeV, where the first error is statistical and the second error is systematic. The sensitivity of the result to this assumption is discussed. We have reduced the dependence of our result on the model ofb hadron semileptonic decay by taking into account the correlation between the model dependence of the branching fractions measured at the ϒ(4S) and of our kinematic acceptance for electrons.
Published: 1992

32. Evidence for b-flavoured baryon production in Z0 decays at LEP

Author: J. Allison, G. Duckeck, R. Ströhmer, D. Strom, G. T. Zorn, G. G. Hanson, A. Astbury, C. Y. Chang, M. Yurko, P. W. Jeffreys, F. S. Merritt, B. C. Shen, H. M. Bosch, Wolfram Dietrich Zeuner, H. M. Fischer, J. Hart, P. Taras, O. Ganel, D. C. Imrie, A. M. Lee, Margret Fincke-Keeler, A. K. Honma, W. G. Scott, J. von Krogh, A. J. Martin, J. A. McKenna, P. G. Estabrooks, R. K. Keeler, A. Michelini, A. C. Janissen, G. Giacomelli, R. F. McGowan, R. Kowalewski, H. O. Ogren, Christoph Geich-Gimbel, E.J. Prebys, M. M. Deninno, J. Kroll, F. X. Gentit, J. E. Conboy, M. Ogg, P. Ashton, A. Pouladdej, K. Riles, P. Pfister, G. Beaudoin, G. P. Siroli, Dave Robinson, L. A. del Pozo, Y. Yang, R. Van Kooten, M. S. Dixit, Frans Meijers, R. Mir, S. A. Robins, D. Pitman, C. K. Hargrove, P. M. Watkins, H. Mes, H. Oh, P. F. Harrison, M. J. Losty, I. P. Duerdoth, M. H. Lehto, J. M. Lorah, Shlomo Dado, P. D. Acton, Stephen Lloyd, D. A. Hinshaw, Michael Dittmar, P. Igo-Kemenes, G. Maringer, D. E. Plane, W. Mohr, G. Yekutieli, J. G. Layter, B. B. Brabson, N. Wermes, D. G. Fong, Ehud Duchovni, M. F. Turner, H. Jeremie, M. Hansroul, P. Poffenberger, T. Mouthuy, Stephen Hillier, M. J. Oreglia, X. C. Lou, G. M. Dallavalle, K. Stephens, Paul Kyberd, F. K. Loebinger, J. R. McNutt, Kiyotomo Kawagoe, R. Shypit, T. Behnke, A. A. Carter, R. E. Hughes-Jones, U. Maur, Giora Mikenberg, Erez Etzion, S. Sanghera, J. Gascon, I. Wingerter, R. J. Homer, Tohru Takeshita, H. von der Schmitt, S. J. Pawley, P. Berlich, M. W. Redmond, J. M. Roney, H. Ihssen, D. J.P. Dumas, O. Schaile, John Hobbs, D. Axen, L. Köpke, P. Singh, Silvia Arcelli, A. Gaidot, Georges Azuelos, E. do Couto e Silva, S. W. Gensler, J. R. Carter, G. N. Patrick, A. Simon, Otmar Biebel, C. Moisan, J. P. Walker, M. Kuwano, T. Wlodek, P. Weber, M. Sproston, A. M. Rossi, J. P. Martin, P. Teixeira-Dias, S. Schreiber, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, T. J. McMahon, T. Kobayashi, D. E. Klen, Gareth J. Barker, D. G. Charlton, D. L. Wagner, M. Couch, T. Tsukamoto, S. Levegrün, V. Gibson, R. W. L. Jones, G. Quast, R. W. Springer, Alexander Wagner, Claude Leroy, A. Rollnik, J. F. Kral, P. Routenburg, K. W. Bell, J. Hagemann, J. Ludwig, K. Runge, A. Dieckmann, P. Bock, J. W. Gary, P. E.L. Clarke, J. P. Pansart, J. Banks, Max Weber, J. Schwiening, R. K. Carnegie, Shlomit Tarem, R. Humbert, G. A. Snow, C. P. Ward, S. De Jong, J. C. Hill, S. Weisz, J. A. Wilson, N. I. Geddes, R. D. Heuer, S. Bougerolle, F. Odorici, J. R. McMahon, Misao Sasaki, Fabrizio Fabbri, D. J. Miller, D. Van den plas, W. Schappert, B. Boden, T. Kawamoto, P. Debu, B. Poli, Horst Breuker, Phillip Allport, P. Le Du, H. Kreutzmann, B. Panzer-Steindel, John Baines, Marcello Mannelli, D. R. Rust, S. Orito, M. Rosvick, P. S. Wells, O. Runolfsson, J. Mildenberger, Harold Nguyen, M. Jobes, U. Binder, C. J. Virtue, S. Rossberg, G. D. Lafferty, C. J. Oram, P. Lennert, Gideon Alexander, Paolo Capiluppi, P. Schenk, W. R. Gibson, C. Ho, M. Coupland, Gideon Bella, H. J. Burckhart, P. Scharff-Hansen, Claudio Grandi, C. Wahl, D. R. Ward, R. Yaari, H. Takeda, A. Beck, G. Transtromer, E. Heflin, S. Bethke, W. J. Larson, R. M. Brown, Marco Cuffiani, Lorne Levinson, R. P. Middleton, M. W. Moss, Jacqueline Batley, F. C. Grant, M. Jimack, B. W. Kennedy, M. A. Whalley, K. J. Anderson, T. R. Wyatt, F. G. Oakham, P. M. Hattersley, R. J. Barlow, H. Przysiezniak, C. P. Howarth, R. G. Kellogg, B. P. O'Neill, S. Wotton, A. M. Smith, Stefano Marcellini, James Letts, G. Vasseur, J. Goldberg, A. Buijs, J. E. Pilcher, B. Lorazo, B. Nellen, P. Leblanc, Andris Skuja, I. J. Bloodworth, H. G. Evans, M. J. Goodrick, I. Cohen, Tetsuro Mashimo, M. Settles, D. Hochman, N. J. Thackray, M. Hauschild, A. D. Schaile, P. Paschievici, N. K. Watson, G. W. Wilson, D. Karlen, J. D. Gillies, G. A. Bahan, V. H. Winterer, T. J. Smith, P. Mättig, S. R. Hou, C. M. Hawkes, M. Cooper, Daniel Lellouch, N. C. Wood, Takehiko Mori, W. Corn, S. W. O'Neale, Peter R Hobson, Sachio Komamiya, E. Ros, A. T. Watson, C. Fukunaga, T. P. Kokott, Rene Brun, F. Lamarche, R. J. Hemingway, P. Jovanovic, Austin Ball, D. Menszner, Alessandro Montanari, W. J. Collins, Randall Sobie, T. W. Pritchard, P. A. Elcombe, D. L. Rees, J. Becker, and G. J. VanDalen
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Branching fraction, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Electron, Nuclear physics, Baryon, High Energy Physics::Experiment, Particle Physics - Experiment, Boson
Abstract: We observe evidence for the production of b-flavoured baryons in decays of the Z 0 boson with the OPAL detector at LEP. We find 68 Λl − , Λ l + candidates in 458 583 hadronic Z 0 decays. We interpret this as a signal of 55 ± 9 +0.3 −3.1 events from the semi-leptonic decays of b baryons. Assuming weakly decaying b baryons produced in Z 0 decays are mostly Λ b particles, we measure the product branching ratio (Γ b b /Γ had ) f ( b →Λ b ) B (Λ b →Λl − v X ) , averaged over the electron and muon channels, to be (6.2±1.0±1.5)×10 −4 .
Published: 1992

33. Test of CP-invariance in e+e−→Z0→τ+τ− and a limit on the weak dipole moment of the τ lepton

Author: D. J. Miller, B. B. Brabson, C. M. Hawkes, M. Cooper, Silvia Arcelli, Daniel Lellouch, Takehiko Mori, D. G. Fong, J. Gascon, Gideon Bella, H. von der Schmitt, H. J. Burckhart, Jacqueline Batley, P. S. Wells, C. J. Virtue, R. Mir, H. Oh, D. Axen, A. Jawahery, Terry Richard Wyatt, G. Beaudoin, T. Mouthuy, P. Singh, R. W. L. Jones, P. Le Du, H. Kreutzmann, B. Panzer-Steindel, M. Coupland, N. K. Watson, B. P. O'Neill, R. Van Kooten, P. E.L. Clarke, P. G. Estabrooks, R. K. Keeler, M. Hansroul, G. Tysarczyk-Niemeyer, J. W. Gary, F. C. Grant, M. A. Whalley, D. Pitman, M. H. Lehto, S. Wotton, P. M. Watkins, Marcello Mannelli, Shlomo Dado, Sachio Komamiya, M. Yurko, E. Ros, A. T. Watson, P. W. Jeffreys, Peter Sherwood, M. J. Oreglia, Phillip Allport, M. Jimack, John Allison, A. Buijs, B. C. Shen, R. W. Springer, Alexander Wagner, P. Igo-Kemenes, G. Maringer, R. J. Homer, I. Wingerter, M. W. Moss, T. P. Kokott, Rene Brun, T. J. Smith, H. O. Ogren, Christoph Geich-Gimbel, U. Biebel, A. M. Rossi, H. Jeremie, Andris Skuja, X. C. Lou, A. M. Lee, P. Mättig, J. Hagemann, S. J. Pawley, R. E. Hughes-Jones, U. Maur, J. Ludwig, A. K. Honma, A. Astbury, M. M. Deninno, K. Runge, P. Bock, O. Ganel, P. Berlich, L. Köpke, Tetsuro Mashimo, T. Tsukamoto, S. Levegrün, Giora Mikenberg, J. Kroll, J. M. Lorah, F. Odorici, R. G. Kellogg, A. J. Martin, W. G. Scott, E. do Couto e Silva, K. Riles, P. M. Hattersley, W. Mohr, I. J. Bloodworth, F. X. Gentit, H. M. Fischer, C. Moisan, J. R. Carter, D. C. Imrie, G. N. Patrick, J. P. Walker, S. Bougerolle, J. E. Conboy, M. Ogg, A. Michelini, M. Settles, C. Fukunaga, A. C. Janissen, R. Kowalewski, Stefano Marcellini, A. Pouladdej, J. Banks, R. Yaari, James Letts, S. Weisz, S. W. O'Neale, Peter R Hobson, P. Teixeira-Dias, F. Lamarche, A. Simon, S. Bethke, F. S. Merritt, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, Marco Cuffiani, W. Gorn, Horst Breuker, G. P. Siroli, Erez Etzion, G. W. Wilson, Gareth J. Barker, G. A. Bahan, D. Karlen, D. R. Rust, M. Jobes, D. G. Charlton, D. L. Wagner, U. Binder, S. A. Robins, M. J. Losty, G. A. Snow, C. P. Ward, R. J. Hemingway, Claude Leroy, J. Mildenberger, C. Wahl, Harold Nguyen, Gideon Alexander, P. Lennert, J. P. Pansart, D. A. Hinshaw, Shlomit Tarem, A. Gaidot, J. A. McKenna, M. Kuwano, T. Wlodek, M. Couch, P. Scharff-Hansen, M. Sproston, W. J. Larson, R. F. McGowan, R. Humbert, Paolo Capiluppi, P. Schenk, H. Mes, I. P. Duerdoth, Kiyotomo Kawagoe, A. M. Smith, A. Dieckmann, John Hobbs, T. Behnke, Margret Fincke-Keeler, C. P. Howarth, G. Vasseur, B. Lorazo, S. Rossberg, W. R. Gibson, P. Routenberg, C. J. Oram, N. I. Geddes, P. Jovanovic, Tohru Takeshita, Paul Kyberd, F. K. Loebinger, J. M. Roney, Austin Ball, N. Wermes, P. A. Elcombe, R. P. Middleton, W. J. Collins, T. Kawamoto, C. K. Hangrove, Georges Azuelos, J. E. Pilcher, G. Duckeck, R. Ströhmer, B. Boden, C. Ho, M. W. Redmond, B. Poli, J. Goldberg, D. Strom, P. Weber, G. T. Zorn, Randall Sobie, G. D. Lafferty, A. Rollnik, D. Menszner, D. L. Rees, J. Becker, J. F. Kral, B. Nellen, Claudio Grandi, K. W. Bell, S. Orito, H. M. Bosch, Wolfram Dietrich Zeuner, Max Weber, M. Rosvick, P. Leblanc, G. J. VanDalen, J. C. Hill, Misao Sasaki, A. Beck, H. G. Evans, M. J. Goodrick, T. W. Pritchard, I. Cohen, E. Heflin, Ehud Duchovni, R. Shypit, R. M. Brown, Alessandro Montanari, Lorne Levinson, A. D. Schaile, B. W. Kennedy, V. H. Winterer, H. Ihssen, O. Runolfsson, J. D. Gillies, O. Schaile, S. R. Hou, D. E. Plane, R. J. Barlow, Stephen Hillier, G. M. Dallavalle, S. W. Gensler, M. Hauschild, D. J.P. Dumas, T. Kobayashi, P. Paschievici, H. Takeda, F. G. Oakham, J. Hart, J. von Krogh, P. Ashton, Dave Robinson, L. A. del Pozo, S. Schreiber, T. J. McMahon, Y. Yang, J. Schwiening, R. K. Carnegie, P. F. Harrison, J. A. Wilson, P. D. Acton, Stephen Lloyd, W. Schappert, Michael Dittmar, H. Przysiezniak, G. Yekutieli, A. A. Carter, P. Pfister, K. J. Anderson, C. Y. Chang, P. Taras, D. E. Klem, M. F. Turner, P. Poffenberger, D. Hochman, N. J. Thackray, K. Stephens, J. R. McNutt, V. Gibson, G. Quast, John Baines, D. R. Ward, G. Transtromer, G. G. Hanson, G. Giacomelli, E.J. Prebys, M. S. Dixit, Frans Meijers, J. P. Martin, S. De Jong, N. C. Wood, P. Debu, J. G. Layter, and S. Sanghera
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Dipole, Neutral current, Electron–positron annihilation, High Energy Physics::Phenomenology, Moment (physics), High Energy Physics::Experiment, Observable, Expectation value, Signature (topology), Lepton
Abstract: Using a sample of 5558 Z 0 → τ + τ − decays produced at LEP a direct test of CP -invariance in the neutral current reaction e + e − → τ + τ − is performed. Samples of events where eachy τ decays into a single particle have been isolated for the construction of CP -odd observables. Three different event classes are considered: lepton-lepton, lepton-hadron, and hadron-hadron. No evidence for a non-zero expectation value of the considered CP -observables and hence for CP -violation is observed. Quantitatively, we deduce from this null result an estimate on the weak dipole moment d τ (m 2 Z = (−4.5 ± 5.3 ± 1.4) × 10 −17 e cm for the lepton-lepton signature and d τ (m 2 Z = (1.4 ± 3.7 ± 1.3) × 10 −17 e cm for the hadron-hadron signature. Combining these results we place a limit with 95% confidence of | d τ |⩽7.0 × 10 −17 e cm.
Published: 1992

34. A global determination of $$\alpha _s (M_{Z^0 } )$$ at LEP

Author: John Hart, H. Mes, H. O. Ogren, Christoph Geich-Gimbel, R. Mir, H. Oh, Tohru Takeshita, I. P. Duerdoth, G. G. Hanson, M. W. Moss, Silvia Arcelli, D. Hochman, N. J. Thackray, Horst Breuker, M. M. Deninno, P. M. Hattersley, J. M. Lorah, J. Kroll, F. X. Gentit, G. Giacomelli, Georges Azuelos, W. Mohr, John Hobbs, J. E. Conboy, M. Ogg, H. Takeda, W. R. Gibson, F. G. Oakham, E.J. Prebys, N. Wermes, R. Van Kooten, J. F. Kral, K. W. Bell, C. Ho, D. C. Imrie, M. J. Oreglia, P. Igo-Kemenes, A. Pouladdej, G. Maringer, H. Jeremie, R. E. Hughes-Jones, U. Maur, Ehud Duchovni, C. J. Virtue, R. Shypit, M. S. Dixit, V. Gibson, E. do Couto e Silva, Max Weber, D. Pitman, M. H. Lehto, Frans Meijers, J. von Krogh, A. Beck, J. C. Hill, E. Heflin, Misao Sasaki, B. B. Brabson, A. Astbury, T. R. Wyatt, D. G. Fong, G. D. Lafferty, P. Ashton, M. Hauschild, F. Lamarche, G. P. Siroli, R. M. Brown, H. Ihssen, O. Ganel, J. Gascon, H. von der Schmitt, R. J. Barlow, R. J. Hemingway, P. Singh, A. J. Martin, Dave Robinson, P. E.L. Clarke, J. P. Martin, Lorne Levinson, F. S. Merritt, A. D. Schaile, D. Axen, H. Przysiezniak, P. Paschievici, A. Gaidot, M. Kuwano, T. Wlodek, B. C. Shen, M. Sproston, A. Jawahery, S. De Jong, I. J. Bloodworth, G. N. Patrick, L. A. del Pozo, P. S. Wells, S. W. Gensler, B. W. Kennedy, K. Riles, P. Jovanovic, F. Odorici, P. G. Estabrooks, A. K. Honma, J. W. Gary, R. K. Keeler, Kiyotomo Kawagoe, Austin Ball, W. G. Scott, A. Dieckmann, G. Tysarczyk-Niemeyer, V. H. Winterer, T. Kobayashi, S. J. Pawley, M. Yurko, Marcello Mannelli, D. Menszner, R. W. L. Jones, P. W. Jeffreys, P. A. Elcombe, P. Debu, M. Jobes, U. Binder, J. A. McKenna, Peter Sherwood, R. Kowalewski, Michael Dittmar, G. Yekutieli, A. Simon, Otmar Biebel, P. Berlich, C. K. Hargrove, J. M. Roney, P. M. Watkins, S. R. Hou, A. M. Lee, R. W. Springer, Alexander Wagner, S. Bougerolle, P. Scharff-Hansen, D. E. Klem, W. J. Larson, Alessandro Montanari, R. F. McGowan, L. Köpke, M. Coupland, R. Yaari, D. G. Charlton, D. L. Wagner, M. Couch, A. A. Carter, P. Weber, J. Hagemann, P. Le Du, H. Kreutzmann, J. G. Layter, G. Beaudion, B. Panzer-Steindel, J. Ludwig, S. Bethke, D. L. Rees, J. Becker, K. Runge, G. A. Snow, C. P. Ward, K. J. Anderson, P. Bock, I. Wingerter, Marco Cuffiani, R. Humbert, M. J. Losty, J. D. Gillies, M. F. Turner, G. J. VanDalen, C. Fukunaga, A. M. Smith, G. Vasseur, B. Lorazo, O. Schaile, N. C. Wood, F. C. Grant, M. A. Whalley, S. Sanghera, M. Settles, D. R. Rust, Gideon Bella, S. Schreiber, Y. Yang, Andris Skuja, D. J. Miller, D. E. Plane, T. J. McMahon, H. J. Burckhart, Jacqueline Batley, J. Schwiening, J. Allison, P. F. Harrison, T. Kawamoto, Tetsuro Mashimo, Stephen Hillier, N. K. Watson, G. M. Dallavalle, R. K. Carnegie, G. Duckeck, R. Ströhmer, J. A. Wilson, Shlomo Dado, D. Strom, P. D. Acton, Stephen Lloyd, W. Gorn, P. Lennert, S. Orito, G. T. Zorn, W. J. Collins, W. Schappert, M. Rosvick, O. Runolfsson, D. J.P. Dumas, X. C. Lou, G. A. Bahan, Randall Sobie, H. M. Bosch, Wolfram Dietrich Zeuner, A. Buijs, T. W. Pritchard, Sachio Komamiya, Giora Mikenberg, C. Y. Chang, Claudio Grandi, P. Taras, E. Ros, A. T. Watson, D. A. Hinshaw, Gideon Alexander, Paolo Capiluppi, P. Schenk, C. Wahl, T. Behnke, B. P. O'Neill, C. P. Howarth, G. W. Wilson, D. Karlen, J. E. Pilcher, J. Banks, S. Wotton, S. Weisz, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, T. P. Kokott, Rene Brun, P. Poffenberger, T. J. Smith, Claude Leroy, J. P. Pansart, Erez Etzion, P. Mättig, Gareth J. Barker, C. M. Hawkes, M. Cooper, Daniel Lellouch, Takehiko Mori, Shlomit Tarem, S. Rossberg, C. J. Oram, S. W. O'Neale, Peter R Hobson, R. P. Middleton, J. Goldberg, B. Nellen, P. Leblanc, C. Moisan, J. P. Walker, H. G. Evans, P. Teixeira-Dias, M. J. Goodrick, I. Cohen, M. Hansroul, R. J. Homer, Margret Fincke-Keeler, J. Mildenberger, Harold Nguyen, P. Pfister, Paul Kyberd, F. K. Loebinger, M. W. Redmond, A. Rollnik, M. Jimack, P. Routenberg, N. I. Geddes, B. Boden, B. Poli, R. G. Kellogg, P. P. Allport, T. Mouthuy, Stefano Marcellini, K. Stephens, J. R. McNutt, James Letts, A. M. Rossi, G. Quast, T. Tsukamoto, John Baines, S. Levegrün, H. M. Fischer, D. R. Ward, A. Michelini, G. Transtromer, A. C. Janissen, S. A. Robins, and J. R. Carter
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Branching fraction, Electron–positron annihilation, Hadron, Perturbative QCD, Observable, Parton, Nuclear physics, Renormalization, High Energy Physics::Experiment, Resummation, Engineering (miscellaneous)
Abstract: The value of the strong coupling constant, $$\alpha _s (M_{Z^0 } )$$ , is determined from a study of 15 different observables in hadronicZ 0 and τ decays. The study includes global event shape variables, jet production rates, energy correlations, theZ 0 line shape and decay asymmetries and the hadronic branching fraction of τ-leptons. Differences between the αs values from the different observables can be consistently attributed to unknown higher order contributions to the calculations. These uncertaities may be parametrized by variations of the renormalization scale and of the parton virtuality to which the data are corrected, separately for each observable, resulting in a consistent description of the event shapes, jet rates and energy correlations with the value $$\alpha _s (M_{Z^0 } ) = 0.122_{ - 0.005}^{ + 0.006} $$ in . The error is dominated by the theoretical uncertainties. Application of recent calculations which include the resummation of leading and next-to-leading logarithms to all orders for some observables confirm this result with a reduced sensitivity to renormalization scale variations. TheZ 0 line shapes and τ-lepton branching ratios yield $$\alpha _s (M_{Z^0 } ) = 0.148 \pm 0.021$$ and $$\alpha _s (M_{Z^0 } ) = 0.123_{ - 0.007}^{ + 0.006} $$ , respectively, in . These measurements and their uncertainties are entirely independent of each other and from event shape and jet observables; the good agreement of the resulting αs values thus constitutes an important consistency check of the reliability of perturbative QCD.
Published: 1992

35. Measurement of B00 mixing in hadronic Z0 decays

Author: Kiyotomo Kawagoe, O. Ganel, J. Gascon, D. Axen, J. M. Roney, P. Weber, A. Wagner, Andris Skuja, R. P. Middleton, P. Le Du, M. Hauschild, B. Panzer-Steindel, D. E. Plane, Tetsuro Mashimo, J. L. Pinfold, C. Y. Chang, Mitsuaki Nozaki, G. Beaudoin, Stephen Hillier, G. M. Dallavalle, H. Mes, R. Van Kooten, M. H. Lehto, Sachio Komamiya, W. Gorn, Phillip Allport, Tohru Takeshita, P. Poffenberger, A. Astbury, F. K. Loebinger, M. W. Redmond, T. Behnke, R. Mir, H. Oh, R. M. Brown, F. C. Grant, M. A. Whalley, G. J. Barker, G. Yekutieli, D. J.P. Dumas, G. Mikenberg, I. P. Duerdoth, F. S. Merritt, Paolo Capiluppi, G. A. Bahan, G. P. Siroli, J. F. Kral, A. K. Honma, P. R. Hobson, E. Ros, A. T. Watson, G. Vasseur, A. Buijs, M. W. Moss, O. Biebel, P. M. Hattersley, A. Gaidot, N. Wermes, X. C. Lou, E. Etzion, S. J. Pawley, O. Runolfsson, John Hobbs, J. P. Pansart, P. Berlich, Claus Kleinwort, L. Köpke, R. Shypit, D. E. Klem, M. Jobes, U. Binder, G. Alexander, G. Bella, P. E.L. Clarke, R. J. Hemingway, P. Scharff-Hansen, W. J. Larson, C. Ho, C. Geich-Gimbel, Max Weber, M. J. Oreglia, J. Schwiening, P. D. Acton, Claudio Grandi, S. A. Robins, H. Ihssen, N. J. Thackray, K. Stephens, D. A. Hinshaw, H. J. Burckhart, M. Cooper, J. A. McKenna, E. Heflin, J. C. Hill, Misao Sasaki, M. F. Turner, M. Jimack, Jacqueline Batley, J. von Krogh, A. M. Smith, S. W. Gensler, G. Maringer, A. M. Lee, Rene Brun, M. Hansroul, B. W. Kennedy, B. C. Shen, J. M. Lorah, J. Banks, C. Wahl, H. M. Fischer, J. D. Gillies, D. C. Imrie, N. C. Wood, S. Tarem, S. Weisz, B. Lorazo, P. Ashton, Dave Robinson, J. Goldberg, M. Coupland, R. D. Heuer, T. P. Kokott, W. Mohr, C. P. Howarth, J. R. Carter, John Allison, P. Jovanovic, Austin Ball, D. Menszner, R. G. Kellogg, T. J. Smith, L. A. del Pozo, J. E. Pilcher, T. J. McMahon, C. Leroy, Fabrizio Fabbri, R. W.L. Jones, D. Van den plas, V. Gibson, R. J. Homer, M. Rosvick, G. A. Snow, C. P. Ward, P. A. Elcombe, R. K. Carnegie, G. Azuelos, B. B. Brabson, P. Mättig, D. G. Fong, S. Schreiber, Alessandro Montanari, H. von der Schmitt, G. N. Patrick, T. Kobayashi, J. G. Layter, A. A. Carter, B. Poli, Stefano Marcellini, J. A. Wilson, D. Pitman, R. Kowalewski, P. Debu, John Baines, E. Duchovni, D. R. Rust, B. Nellen, M. Sproston, W. Schappert, D. L. Rees, J. Becker, S. Bethke, G. Quast, Marco Cuffiani, C. M. Hawkes, D. G. Charlton, James Letts, M. Couch, P. Schenk, P. Lennert, J. Hart, O. Schaile, P. Taras, J. W. Gary, C. J. Oram, C. Fukunaga, M. J. Losty, A. J. Martin, C. Moisan, Marcello Mannelli, G. J. VanDalen, D. R. Ward, R. Humbert, P. F. Harrison, K. J. Anderson, Takehiko Mori, Michael Dittmar, S. Sanghera, J. Hagemann, P. S. Wells, C. J. Virtue, N. I. Geddes, P. Pfister, A. Michelini, A. C. Janissen, Terry Richard Wyatt, P. W. Jeffreys, A. Jawahery, R. Yaari, M. Fincke-Keeler, R. J. Barlow, G. Tysarczyk-Niemeyer, D. J. Miller, J. Mildenberger, Harold Nguyen, W. R. Gibson, A. Simon, T. W. Pritchard, Y. Yang, T. Kawamoto, Peter Sherwood, F. Odorici, D. Lellouch, M. Kuwano, R. W. Springer, J. Ludwig, P. Routenburg, S. Orito, A. Dieckmann, K. Runge, P. Bock, F. Lamarche, N. K. Watson, I. Cohen, D. Hochman, B. Boden, M. Yurko, G. Eckerlin, S. De Jong, I. J. Bloodworth, J. P. Walker, P. Teixeira-Dias, T. Mouthuy, G. Duckeck, R. Ströhmer, A. Rollnik, L. Levinson, W. J. Collins, G. D. Lafferty, D. Strom, H. Takeda, G. T. Zorn, F. G. Oakham, R. F. McGowan, P. Paschievici, H. M. Bosch, G. W. Wilson, M. Settles, H. O. Ogren, A. M. Rossi, P. Leblanc, Wolfram Dietrich Zeuner, M. M. Deninno, J. Kroll, J. P. Martin, T. Tsukamoto, S. Dado, G. G. Hanson, J. E. Conboy, M. Ogg, H. Kreutzmann, A. Pouladdej, A. D. Schaile, G. Giacomelli, V. H. Winterer, S. W. O'Neale, E.J. Prebys, S. R. Hou, D. Karlen, M. S. Dixit, Frans Meijers, Silvia Arcelli, U. Maur, S. Wotton, M. Weymann, H. E. Stier, P. G. Estabrooks, P. M. Watkins, P. Kyberd, I. Wingerter, S. Rossberg, K. W. Bell, P. Igo-Kemenes, A. Beck, R. E. Hughes-Jones, W. G. Scott, K. Riles, H. Jeremie, P. Singh, C. K. Hargrove, B. Holl, S. Levegrün, I. Zacharov, R. Sobie, Horst Breuker, S. Bougerolle, R. K. Keeler, M. J. Goodrick, G. Transtromer, H. Przysieniak, J. R. McNutt, S. L. Lloyd, B. P. O'Neill, and F. X. Gentit
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Electron, Jet (particle physics), Bottom quark, Nuclear physics, High Energy Physics::Experiment, Mixing (physics), Lepton
Abstract: From a sample of approximately 135 000 hadronic Z0 decays recorded with the OPAL detector, 1 536 events were selected with two lepton candidates, either electrons or muons. A signal for B0 B 0 mixing was observed using the sign of the lepton charge to tag the charge of the b quark in decaying b-flavoured hadrons. A flavour discriminating variable was constructed from the lepton momentum and its component perpendicular to the jet axis. By fitting the fraction of events in which the two lepton charges are of the same sign, as a function of this variable, the average mixing parameter was measured to be χ = 0.145+0.041-0.035 ± 0.018, where the first error is statistical and the second is systematic.
Published: 1992

36. An improved measuremebts of αS (MZ0) using energy correlations with the OPAL detector at LEP

Author: H. M. Fischer, P. A. Elcombe, T. Mouthuy, T. J. McMahon, P. Routenburg, M. Cooper, B. Poli, P. Igo-Kemenes, Sachio Komamiya, A. M. Rossi, P. Debu, T. Tsukamoto, A. Michelini, S. Sanghera, J. Schweining, B. C. Shen, E. Ros, A. T. Watson, I. P. Duerdoth, F. Lamarche, R. Yaari, M. F. Turner, Richard Keeler, P. Jovanovic, D. J.P. Dumas, M. Hansroul, H. Ihssen, Austin Ball, D. L. Rees, W. Schappert, H. O. Ogren, O. Biebel, M. Jimack, John Allison, B. P. O'Neill, A. J. Martin, Rene Brun, Alessandro Montanari, M. Coupland, Gideon Bella, G. Vasseur, R. Mir, A. Astbury, P. Berlich, P. Lennert, R. J. Homer, S. Bougerolle, D. R. Rust, M. W. Moss, M. Sproston, G. J. VanDalen, A. D. Schaile, A. M. Lee, P. Poffenberger, J. Kroll, P. M. Hattersley, K. Stephens, U. Binder, H. Oh, R. G. Kellogg, P. Taras, R. M. Brown, S. W. Gensler, G. Maringer, F. X. Gentit, B. Boden, P. Mättig, E. Etzion, B. B. Brabson, N. C. Wood, W. J. Collins, S. De Jong, J. E. Conboy, T. Kobayashi, H. J. Burckhart, Jacqueline Batley, C. Geich-Gimbel, R. E. Hughes-Jones, G. W. Wilson, D. G. Fong, H. von der Schmitt, D. Menszner, D. Axen, Stefano Marcellini, J. P. Walker, A. C. Janissen, D. Karlen, A. Dieckmann, G. J. Barker, R. K. Carnegie, James Letts, M. Fincke-Keeler, G. D. Lafferty, R. Sobie, G. P. Siroli, Phillip Allport, P. Paschievici, M. Kuwano, P. Teixeira-Dias, A. A. Carter, M. Ogg, Tohru Takeshita, N. K. Watson, P. Singh, R. Shypit, G. Transtromer, G. A. Snow, H. E. Stier, R. Van Kooten, O. Schaile, M. H. Lehto, H. M. Bosch, D. C. Imrie, F. Odorici, V. Gibson, J. L. Pinfold, F. S. Merritt, John Baines, A. Rollnik, F. K. Loebinger, K. W. Bell, C. P. Ward, Kiyotomo Kawagoe, A. Beck, D. E. Plane, W. R. Gibson, Stephen Hillier, M. J. Goodrick, H. Takeda, H. Jeremie, J. W. Gary, H. Kreutzmann, Marcello Mannelli, W. G. Scott, J. Becker, K. J. Anderson, P. S. Wells, P. E.L. Clarke, G. M. Dallavalle, K. Runge, J. P. Martin, T. W. Pritchard, H. Przysiezniak, A. Wagner, J. F. Kral, C. J. Virtue, H. Mes, Terry Richard Wyatt, G. Duckeck, Richard J Hemingway, C. J. Oram, J. M. Roney, O. Runolfsson, M. Jobes, F. G. Oakham, E. Duchovni, P. G. Estabrooks, P. Kyberd, C. K. Hargrove, J. A. McKenna, Paolo Capiluppi, M. W. Redmond, P. Pfister, J. C. Hill, D. R. Ward, F. C. Grant, M. A. Whalley, P. Schenk, P. Scharff-Hansen, S. W. O'Neale, Peter R Hobson, T. P. Kokott, J. Hart, G. Tysarczyk-Niemeyer, Claudio Grandi, C. Ho, W. J. Larson, D. Pitman, Misao Sasaki, R. F. McGowan, A. Pouladdej, Marco Cuffiani, J. M. Lorah, M. M. Dennino, G. Mikenberg, D. Lellouch, C. Y. Chang, S. Rossberg, P. Bock, A. Buijs, S. J. Pawley, E. Heflin, G. G. Hanson, J. P. Pansart, M. J. Oreglia, Y. Yang, N. I. Geddes, R. J. Barlow, G. Alexander, B. Holl, P. Weber, S. Levegrün, P. F. Harrison, Claus Kleinwort, L. Köpke, S. Tarem, A. Gaidot, S. R. Hou, D. J. Miller, R. Humbert, G. N. Patrick, W. Mohr, S. Bethke, P. D. Acton, B. W. Kennedy, M. Hauschild, John Hobbs, S. A. Robins, D. Hochman, C. Fukunaga, I. Zacharov, M. J. Losty, G. Giacomelli, Stephen Lloyd, M. Yurko, J. Mildenberger, E.J. Prebys, Horst Breuker, Mitsuaki Nozaki, P. W. Jeffreys, X. C. Lou, A. M. Smith, C. Wahl, T. Behnke, C. Leroy, M. S. Dixit, B. Lorazo, G. Quast, P. Leblanc, S. Dado, J. Banks, G. Azuelos, Frans Meijers, P. Le Du, S. Weisz, R. D. Heuer, J. R. Carter, B. Panzer-Steindel, Fabrizio Fabbri, D. A. Hinshaw, D. Van den plas, M. Weber, L. Levinson, B. Nellen, J. G. Layter, D. E. Klem, A. K. Honma, D. G. Charlton, O. Ganel, K. Riles, M. Couch, G. Eckerlin, G. Beaudoin, N. J. Thackray, Andris Skuja, Harold Nguyen, J. Ludwig, C. P. Howarth, R. Kowalewski, J. Gascon, J. E. Pilcher, S. Schreiber, T. Kawamoto, S. Orito, V. H. Winterer, Tetsuro Mashimo, P. M. Watkins, W. Gorn, G. Yekutieli, M. Rosvick, G. A. Bahan, I. Wingerter, Silvia Arcelli, S. Wotton, A. Simon, M. Weymann, N. Wermes, A. Jawahery, Peter Sherwood, R. W. Springer, J. R. McNutt, U. Maur, D. Strom, G. T. Zorn, Wolfram Dietrich Zeuner, R. Ströhmer, J. A. Wilson, I. Cohen, Michael Dittmar, R. W.L. Jones, J. von Krogh, P. Ashton, Dave Robinson, L. A. del Pozo, J. Goldberg, T. J. Smith, I. J. Bloodworth, C. Moisan, James D Gillies, M. Settles, J. Hagemann, C. M. Hawkes, Takehiko Mori, and R. P. Middleton
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, media_common.quotation_subject, Electron–positron annihilation, Monte Carlo method, Hadron, Asymmetry, Hadronization, Nuclear physics, Renormalization, Correlation function, High Energy Physics::Experiment, Perturbation theory (quantum mechanics), Particle Physics - Experiment, media_common
Abstract: We report on an improved measurement of the value of the strong coupling constant σs at the Z0 peak, using the asymmetry of the energy-energy correlation function. The analysis, based on second-order perturbation theory and a data sample of about 145000 multihadronic Z0 decays, yields αs(Mz0 = 0.118±0.001(stat.)±0.003(exp.syst.)−0.004+0.0009 (theor. syst.), where the theoretical systematic error accounts for uncertainties due to hadronization, the choice of the renormalization scale and unknown higher-order terms. We adjust the parameters of a second-order matrix element Monte Carlo followed by string hadronization to best describe the energy correlation and other hadronic Z0 decay data. The αs result obtained from this second-order Monte Carlo is found to be unreliable if values of the renormalization scale smaller than about 0.15 Ecm are used in the generator.
Published: 1992

37. Measurement of three-jet distributions sensitive to the gluon spin ine + e − annihilations at $$\sqrt s = 91$$ GeV

Author: Phillip Allport, P. W. Jeffreys, A. M. Lee, B. C. Shen, J. D. Hobbs, H. E. Stier, D. A. Hinshaw, G. G. Hanson, P. Tarras, H. Mes, P. G. Estabrooks, R. K. Keeler, A. Simon, J. D. Gillies, I. P. Duerdoth, G. Giacomelli, Gideon Alexander, H. Przysiezniak, C. Y. Chang, N. C. Wood, E.J. Prebys, Otmar Biebel, D. G. Charlton, W. G. Scott, Paolo Capiluppi, P. Schenk, R. J. Barlow, O. Runolfsson, T. Mouthuy, L. Lessard, F. S. Merritt, Mitsuaki Nozaki, P. M. Watkins, M. Couch, D. J. Miller, Claudio Grandi, R. Humbert, M. S. Dixit, Frans Meijers, R. Kowalewski, Margret Fincke-Keeler, M. Jimack, John Allison, N. Wermes, M. A. Whalley, G. A. Snow, C. P. Ward, J. T.M. Chrin, L. Janissen, C. Milstene, Ehud Duchovni, R. Shypit, M. J. Losty, P. Singh, S. Schreiber, B. B. Brabson, J. G. Layter, A. M. Rossi, D. G. Fong, T. Kawamoto, J. Gascon, Kiyotomo Kawagoe, I. Wingerter, B. P. O'Neill, F. Lamarche, G. Beaudoin, A. Buijs, A. P. Wagner, T. J. McMahon, R. G. Kellogg, P. Pfister, T. Tsukamoto, J. Hagemann, H. Ihssen, S. W. Gensler, R. W. L. Jones, S. Levegrün, H. M. Fischer, S. Orito, John H. Schwarz, H. von der Schmitt, W. R. Gibson, G. Duckeck, R. Mir, R. J. Hemingway, Silvia Arcelli, A. Michelini, J. M. Roney, D. Hochman, N. J. Thackray, T. J. Smith, C. Ho, D. Strom, G. T. Zorn, Stefano Marcellini, R. F. McGowan, T. Kobayashi, H. Oh, Shlomo Dado, S. Sanghera, R. K. Carnegie, K. Stephens, C. Fukunaga, P. Jovanovic, J. Goldberg, J. C. Armitage, P. Mättig, H. O. Ogren, J. A. Wilson, Christoph Geich-Gimbel, P. Igo-Kemenes, G. Maringer, F. Odorici, S. A. Robins, J. R. McNutt, Austin Ball, D. Menszner, Alessandro Montanari, H. M. Bosch, D. C. Imrie, Tohru Takeshita, M. M. Deninno, M. J. Oreglia, W. Schappert, H. Jeremie, P. Le Du, H. Kreutzmann, A. Beck, J. Mildenberger, Harold Nguyen, Marcello Mannelli, M. Jobes, U. Binder, E. Heflin, R. M. Brown, Wolfram Dietrich Zeuner, E. K. U. Gross, A. Gaidot, M. Kuwano, P. Scharff-Hansen, Lorne Levinson, C. M. Hawkes, M. Cooper, Daniel Lellouch, G. P. Siroli, B. Nellen, P. Leblanc, M. J. Goodrick, M. Sproston, B. Panzer-Steindel, R. E. Hughes-Jones, U. Maur, I. Cohen, J. Hart, V. Gibson, Y. Yang, P. F. Harrison, J. L. Pinfold, G. Eckerlin, Michael Dittmar, W. J. Larson, D. Axen, A. Jawahery, John Baines, B. W. Kennedy, Georges Azuelos, G. Tysarczyk-Niemeyer, J. Kroll, O. Schaile, F. X. Gentit, J. E. Conboy, S. W. O'Neale, Peter R Hobson, M. Ogg, M. Hansroul, J. R. Carter, K. W. Bell, G. N. Patrick, G. Yekutieli, Gideon Bella, Stephen Lloyd, J. W. Gary, Takehiko Mori, A. D. Schaile, Peter Sherwood, S. Wotton, H. Takeda, Max Weber, K. J. Anderson, J. C. Hill, R. W. Springer, M. Weymann, A. Pouladdej, H. J. Burckhart, D. E. Klem, A. A. Carter, Misao Sasaki, A. M. Smith, Jacqueline Batley, N. I. Geddes, J. Ludwig, K. Runge, G. Vasseur, P. Routenburg, D. R. Ward, F. G. Oakham, P. Bock, Erez Etzion, M. W. Moss, Paul Kyberd, F. K. Loebinger, B. Lorazo, V. H. Winterer, A. Dieckmann, P. M. Hattersley, S. Bougerolle, Andris Skuja, B. Poli, J. Banks, M. W. Redmond, S. R. Hou, Claude Leroy, Gareth J. Barker, Tetsuro Mashimo, J. P. Martin, R. J. Homer, A. Rollnik, S. De Jong, M. F. Turner, P. Poffenberger, J. P. Pansart, N. K. Watson, J. von Krogh, I. J. Bloodworth, P. A. Elcombe, Shlomit Tarem, C. Wahl, W. J. Collins, Sachio Komamiya, A. T. Watson, S. Weisz, P. Ashton, Dave Robinson, Randall Sobie, G. D. Lafferty, C. P. Howarth, W. Gorn, D. E. Plane, T. P. Kokott, Rene Brun, J. E. Pilcher, M. Settles, G. A. Bahan, Stephen Hillier, R. D. Heuer, C. Moisan, J. P. Walker, C. K. Hargrove, T. W. Pritchard, Fabrizio Fabbri, G. M. Dallavalle, P. Teixeira-Dias, S. Rossberg, P. S. Wells, M. Hauschild, C. J. Oram, D. J.P. Dumas, C. J. Virtue, P. Paschievici, Terry Richard Wyatt, D. Van den plas, G. W. Wilson, D. Karlen, M. Coupland, D. L. Rees, P. Debu, J. Becker, D. R. Rust, R. P. Middleton, G. J. VanDalen, P. Lennert, M. H. Letho, R. Van Kooten, J. M. Lorah, W. Mohr, S. J. Pawley, Claus Kleinwort, L. Köpke, X. C. Lou, P. G. Murphy, Giora Mikenberg, P. E.L. Clarke, T. Behnke, B. Holl, I. Zacharov, Horst Breuker, R. Yaari, S. Bethke, Marco Cuffiani, Gunter Quast, A. Astbury, O. Ganel, A. J. Martin, and K. Riles
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Electron–positron annihilation, High Energy Physics::Phenomenology, Scalar (mathematics), Elementary particle, Jet (particle physics), Gluon, Nuclear physics, High Energy Physics::Experiment, Field theory (psychology), Quantum field theory, Engineering (miscellaneous), Spin-½
Abstract: Three-jet variables constructed from multi-hadronic events produced byZ0 decays are compared to theoretical calculations assuming a vector gluon or a hypothetical scalar gluon. The data yield conclusive direct evidence for the former case. The distributions of the reduced energy of the second-most energetic jet and of the cosine of the Ellis-Karliner angle are chosen to demonstrate this effect.
Published: 1991

38. Measurement of branching ratios and τ polarization from τ→eνν−,τ→μνν−,andτ→π(K)ν decays at LEP

Author: Gideon Bella, H. J. Burckhart, Jacqueline Batley, H. M. Fischer, A. Michelini, H. E. Stier, P. E.L. Clarke, J. Hart, Sachio Komamiya, P. G. Estabrooks, T. Behnke, Robin Middleton, C. Milstene, Erez Etzion, B. B. Brabson, S. A. Robins, Y. Yang, D. G. Fong, Andris Skuja, P. Schenk, A. D. Schaile, Tetsuro Mashimo, J. Gascon, W. Gorn, H. von der Schmitt, G. A. Bahan, T. P. Kokott, Rene Brun, Richard Keeler, Marcello Mannelli, Gareth J. Barker, M. Jobes, U. Binder, Shlomit Tarem, P. Scharff-Hansen, W. J. Larson, J. W. Gary, T. Kobayashi, F. Odorici, A. M. Smith, H. Takeda, G. N. Patrick, G. Vasseur, P. F. Harrison, J. R. Carter, B. Lorazo, P. M. Watkins, F. G. Oakham, M. F. Turner, A. M. Lee, J. D. Hobbs, Robert M Brown, F. L. Fabbri, S. Rossberg, K. Stephens, G. G. Hanson, Kiyotomo Kawagoe, N. C. Wood, R. Yaari, Paul Kyberd, S. Bethke, F. K. Loebinger, P. Singh, J. R. McNutt, Claude Leroy, J. P. Pansart, A. P. Wagner, N. Wermes, P. Igo-Kemenes, Marco Cuffiani, J. D. Gillies, B. Poli, V. H. Winterer, G. Giacomelli, I. Wingerter, M. W. Redmond, Ehud Duchovni, M. A. Whalley, R. W. L. Jones, H. Mes, I. P. Duerdoth, J. M. Roney, G. Maringer, F. S. Merritt, J. Goldberg, Tohru Takeshita, P. Pfister, E. K. U. Gross, G. A. Snow, E.J. Prebys, Silvia Arcelli, A. Rollnik, C. P. Ward, H. Ihssen, P. Le Du, A. Gaidot, D. R. Rust, S. W. O'Neale, Peter R Hobson, H. Jeremie, B. Nellen, R. E. Hughes-Jones, M. Kuwano, H. Kreutzmann, M. S. Dixit, B. Panzer-Steindel, S. W. Gensler, G. Mikenberg, A. Buijs, Georges Azuelos, J. C. Armitage, Frans Meijers, S. R. Hou, L. Janissen, T. Mouthuy, D. E. Klem, U. Maur, P. Leblanc, D. J. Miller, Ken W Bell, John Baines, M. Sasaki, P. Lennert, V. Gibson, P. Routenburg, Max Weber, J. G. Layter, C. Moisan, R. J. Barlow, H. Przysiezniak, J. Mildenberger, J. P. Walker, D. E. Plane, M. J. Goodrick, I. Cohen, J. C. Hill, P. Teixeira-Dias, R. F. McGowan, N. K. Watson, A. Dieckmann, Harold Nguyen, B. C. Shen, Stephen Hillier, F. Lamarche, Gunter Quast, G. M. Dallavalle, R. J. Hemingway, N. I. Geddes, Shlomo Dado, D. R. Ward, Phillip Allport, S. Wotton, S. Bougerolle, W. J. Collins, H. O. Ogren, Christoph Geich-Gimbel, G. J. VanDalen, B. P. O'Neill, D. J.P. Dumas, R. Van Kooten, M. H. Lehto, S. Sanghera, O. Runolfsson, M. Weymann, M. W. Moss, M. Sproston, P. S. Wells, M. M. Deninno, J. Kroll, G. Eckerlin, R. Sobie, P. Jovanovic, W. G. Scott, C. J. Virtue, A. M. Rossi, T. Tsukamoto, S. L. Lloyd, C. J. Oram, F. X. Gentit, Austin Ball, P. W. Jeffreys, R. Kowalewski, M. Jimack, G. D. Lafferty, X. C. Lou, W. R. Gibson, Terry Richard Wyatt, A. T. Watson, J. Hagemann, P. M. Hattersley, M. Coupland, J. E. Conboy, D. Menszner, J. P. Martin, M. Ogg, C. Ho, S. J. Pawley, C. Wahl, J. M. Lorah, Gideon Alexander, K. J. Anderson, Alessandro Montanari, T. J. Smith, S. De Jong, A. Beck, E. Heflin, Paolo Capiluppi, T. W. Pritchard, Claus Kleinwort, Claudio Grandi, L. Köpke, A. Pouladdej, R. G. Kellogg, Lorne Levinson, O. Schaile, D. C. Imrie, B. Holl, W. Mohr, M. Hansroul, C. P. Howarth, M. J. Losty, L. Lessard, C. Y. Chang, B. W. Kennedy, Gilles Beaudoin, Stefano Marcellini, P. Debu, J. E. Pilcher, G. P. Siroli, J. Banks, P. Taras, Mitsuaki Nozaki, P. A. Elcombe, I. Zacharov, S. Weisz, R. D. Heuer, D. Van den plas, Horst Breuker, C. Fukunaga, D. Hochman, N. J. Thackray, D. L. Rees, J. Becker, M. Hauschild, R. J. Homer, P. Paschievici, A. Astbury, J. L. Pinfold, O. Ganel, A. J. Martin, K. Riles, P R Poffenberger, C. K. Hargrove, S. Levegrün, S. Schreiber, R. Mir, H. Oh, T. J. McMahon, J. Allison, G. Duckeck, D. Strom, G. T. Zorn, H. M. Bosch, R. K. Carnegie, Wolfram Dietrich Zeuner, J. A. Wilson, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, M. Fincke-Keeler, P. G. Murphy, M. J. Oreglia, Peter Sherwood, R. W. Springer, J. Ludwig, K. Runge, P. Bock, W. Schappert, D. A. Hinshaw, A. Simon, Otmar Biebel, D. G. Charlton, M. Couch, R. Humbert, J. T.M. Chrin, T. Kawamoto, S. Orito, John H. Schwarz, Michael Dittmar, G. Yekutieli, A. A. Carter, P. Mättig, I. J. Bloodworth, M. Settles, J. von Krogh, G. W. Wilson, P. Ashton, Dave Robinson, D. Karlen, C. M. Hawkes, M. Cooper, Daniel Lellouch, R. Shypit, and Takehiko Mori
Subjects: Nuclear physics, Physics, Coupling constant, Nuclear and High Energy Physics, Pion, Muon, Electron–positron annihilation, Weinberg angle, Electron, Pseudovector, Lepton
Abstract: From a sample of 3308 e + e − → τ + τ − events with an estimated background of 1.9%, we find 964 τ → e ν ν , 903 τ → μν ν , and 309 τ → π( K )ν candidates. Efficiency and background estimates determined from both Monte Carlo and control sample studies yield the following branching ratios: B(τ → e ν ν ) = 17.4 ± 0.5 ( stat ) ± 0.4 ( sys )% , B(τ → μν ν ) = 16.8 ± 0.5 ± 0.4%, and B(τ → π( K )ν) = 12.1 ± 0.7 ± 0.5% . These values are in good agreement with previous measurements. The measured lepton branching ratios, when combined with the world-average measured value for the τ lifetime, yield a ratio of the τ Fermi coupling constant to that of the lighter leptons given by G τ / G e, μ = 0.92 ± 0.04, where it is assumed G e = G μ ≡ G e , μ . The average τ polarization at the Z° resonance is measured to be −0.01±0.09 from an analysis of the momentum spectra of the electron, muon, and pion candidates, implying that the ratio of vector to axial vector couplings of the τ to the Z° is ν τ / α τ = 0.01 ± 0.04. The measurements of the average polarizations in the forward and backward hemispheres lead to the efficiency-corrected, forward-backward polarization asymmetry A FB pol = −0.22 ± 0.10, implying for the electron couplings to the Z° the ratio ν e / α e = 0.15±0.07. Since these values for the tau and electron couplings are consistent with one another, we assume lepton universality to derive ν / α = 0.05 ± 0.04 and a value for the weak mixing angle of sin 2 θ W = 0.237 ± 0.009 , with no ambiguity introduced by the relative signs of ν and α.
Published: 1991

39. A search for scalar leptoquarks in Z0 decays

Author: H. E. Stier, P. G. Estabrooks, Erez Etzion, Gareth J. Barker, N. I. Geddes, P. Schenk, A. D. Schaile, Shlomit Tarem, P. M. Watkins, H. Mes, Kiyotomo Kawagoe, S. Rossberg, I. P. Duerdoth, V. H. Winterer, Tohru Takeshita, I. Wingerter, O. Schaile, A. P. Wagner, R. P. Middleton, B. Poli, S. R. Hou, J. M. Roney, Georges Azuelos, G. Beaudoin, L. Janissen, D. J. Miller, K. W. Bell, Max Weber, Misao Sasaki, H. O. Ogren, J. Goldberg, B. C. Shen, Shlomo Dado, H. Takeda, M. Hansroul, Christoph Geich-Gimbel, B. Nellen, N. Wermes, C. Milstene, P. Leblanc, F. Odorici, W. G. Scott, P. S. Wells, F. G. Oakham, C. J. Virtue, O. Runolfsson, X. C. Lou, P. G. Murphy, M. M. Deninno, Terry Richard Wyatt, B. Holl, J. Kroll, R. J. Homer, R. Kowalewski, L. Lessard, Andris Skuja, S. W. O'Neale, Ehud Duchovni, M. Coupland, T. J. Smith, F. X. Gentit, J. E. Conboy, J. D. Gillies, M. Ogg, M. J. Losty, Peter R Hobson, Giora Mikenberg, Silvia Arcelli, Claudio Grandi, P. Igo-Kemenes, D. C. Imrie, Richard Keeler, P. Mättig, I. Zacharov, C. Y. Chang, M. J. Goodrick, A. Pouladdej, I. Cohen, Tetsuro Mashimo, P. Singh, T. Mouthuy, C. Moisan, J. P. Walker, Horst Breuker, R. J. Barlow, G. Maringer, H. Ihssen, H. Jeremie, K. Stephens, C. Fukunaga, C. M. Hawkes, M. Cooper, Daniel Lellouch, R. Shypit, Takehiko Mori, G. K. VanDalen, P. W. Jeffreys, R. Van Kooten, F. S. Merritt, J. R. McNutt, G. P. Siroli, J. D. Hobbs, Claude Leroy, C. Wahl, P. Taras, S. W. Gensler, J. P. Pansart, R. W. L. Jones, N. C. Wood, W. Gorn, R. E. Hughes-Jones, U. Maur, Mitsuaki Nozaki, A. M. Lee, G. G. Hanson, F. Lamarche, D. E. Plane, R. J. Hemingway, Stephen Hillier, P. Le Du, H. Kreutzmann, B. Panzer-Steindel, V. Gibson, M. H. Lehto, M. A. Whalley, G. A. Bahan, J. Mildenberger, Harold Nguyen, Gunter Quast, S. Wotton, T. Kobayashi, G. M. Dallavalle, John Baines, Margret Fincke-Keeler, I. J. Bloodworth, C. P. Howarth, P. Jovanovic, E. K. U. Gross, A. Gaidot, M. Kuwano, Gideon Bella, H. J. Burckhart, N. K. Watson, M. Sproston, G. A. Snow, C. P. Ward, B. B. Brabson, M. Weymann, A. Buijs, J. E. Pilcher, Austin Ball, G. Giacomelli, J. Hart, E.J. Prebys, A. M. Rossi, D. E. Klem, D. R. Ward, M. Settles, D. Menszner, R. F. McGowan, D. G. Fong, Sachio Komamiya, Jacqueline Batley, B. P. O'Neill, Alan Watson, D. J.P. Dumas, P. Pfister, J. L. Pinfold, A. Astbury, J. Gascon, T. Tsukamoto, H. von der Schmitt, Alessandro Montanari, M. W. Moss, O. Ganel, S. Levegrün, H. M. Fischer, A. J. Martin, M. F. Turner, Y. Yang, P. Routenburg, P. M. Hattersley, T. P. Kokott, Rene Brun, J. Hagemann, J. C. Armitage, G. W. Wilson, D. Karlen, K. Riles, G. Eckerlin, M. S. Dixit, Frans Meijers, C. J. Oram, W. R. Gibson, P. F. Harrison, S. Bougerolle, W. J. Collins, S. J. Pawley, C. Ho, Marcello Mannelli, A. Michelini, Paul Kyberd, F. K. Loebinger, C. K. Hargrove, Stephen Lloyd, M. Jobes, U. Binder, D. Hochman, N. J. Thackray, P. Scharff-Hansen, G. D. Lafferty, A. Dieckmann, Claus Kleinwort, P. A. Elcombe, L. Köpke, W. J. Larson, P. Teixeira-Diaz, H. Przysiezniak, D. R. Rust, M. W. Redmond, J. W. Gary, T. W. Pritchard, J. G. Layter, A. Beck, A. Rollnik, A. M. Smith, P. E.L. Clarke, T. Behnke, E. Heflin, G. Vasseur, B. Lorazo, P. Lennert, Phillip Allport, R. M. Brown, S. Sanghera, M. Hauschild, S. A. Robins, R. Sobie, M. Jimack, John Allison, J. P. Martin, Gideon Alexander, Lorne Levinson, Paolo Capiluppi, K. J. Anderson, John Hill, P. Paschievici, B. W. Kennedy, S. De Jong, R. G. Kellogg, J. Banks, D. L. Rees, J. Becker, R. Yaari, S. Weisz, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, S. Bethke, Marco Cuffiani, Stefano Marcellini, P. Debu, P R Poffenberger, J. M. Lorah, W. Mohr, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, R. W. Springer, Michael Dittmar, G. Yekutieli, J. Ludwig, K. Runge, P. Bock, A. Simon, Otmar Biebel, D. G. Charlton, M. Couch, R. Humbert, G. Duckeck, A. A. Carter, J. T.M. Chrin, D. Strom, G. T. Zorn, H. M. Bosch, T. Kawamoto, Wolfram Dietrich Zeuner, S. Orito, John H. Schwarz, D. A. Hinshaw, R. Mir, H. Oh, M. J. Oreglia, J. R. Carter, G. N. Patrick, J. von Krogh, P. Ashton, Dave Robinson, S. Schreiber, T. J. McMahon, R. K. Carnegie, J. A. Wilson, and W. Schappert
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Branching fraction, Electron–positron annihilation, High Energy Physics::Phenomenology, Scalar (physics), Nuclear physics, High Energy Physics::Experiment, Leptoquark, Neutrino, Particle Physics - Experiment, Storage ring, Lepton
Abstract: A search for scalar leptoquarks has been performed with data from the OPAL detector at the e+e− storage ring LEP. In a data sample corresponding to an integrated luminosity of 6.3 pb−1 no evidence for leptoquark production was observed where the leptoquark decays into a quark and either a charged lepton (e, μ, τ) or a neutrino. An upper limit of 1.7 pb on the production cross section for leptoquarks is obtainedassuming a branching ratio of 50% for the decay of the leptoquark into the channels with a charged lepton. Lower limits on the leptoquark mass between 41.4 and 46.4 GeV/c2 at 95% CL are obtained, depending on the effecte SU(2) × U(1) invariant couplings assigned to the leptoquark.
Published: 1991

40. Measurement of theZ 0 line shape parameters and the electroweak couplings of charged leptons

Author: M. Jimack, John Allison, D. Axen, A. Jawahery, G. Tysarczyk-Niemeyer, Peter Sherwood, R. W. Springer, B. Holl, N. C. Wood, C. M. Hawkes, M. Cooper, Daniel Lellouch, J. Ludwig, G. J. Van Dalen, K. Runge, P. Bock, A. Simon, Otmar Biebel, D. G. Charlton, Takehiko Mori, I. Zacharov, Horst Breuker, G. A. Snow, C. P. Ward, M. Couch, A. D. Schaile, R. G. Kellogg, C. Y. Chang, P. Taras, Mitsuaki Nozaki, D. A. Hinshaw, R. Humbert, J. T.M. Chrin, Stefano Marcellini, V. H. Winterer, O. Runolfsson, T. Kawamoto, T. J. Smith, S. Orito, S. Bougerolle, P. Mättig, L. Lessard, John H. Schwarz, T. R. Wyatt, Claudio Grandi, S. R. Hou, Gunter Quast, P. Singh, T. Mouthuy, J. M. Lorah, W. Mohr, R. Mir, H. Oh, I. J. Bloodworth, J. G. Layter, S. Sanghera, F. S. Merritt, M. Settles, R. W. L. Jones, G. Beaudoin, M. J. Oreglia, W. J. Collins, G. D. Lafferty, P. Le Du, J. Hart, Y. Yangh, H. Kreutzmann, B. Panzer-Steindel, H. Przysiezniak, A. M. Rossi, K. J. Anderson, A. Astbury, G. Duckeck, D. Karlen, W. R. Gibson, Tohru Takeshita, D. Strom, P. E.L. Clarke, T. Behnke, Paul Kyberd, F. K. Loebinger, G. Giacomelli, T. Tsukamoto, Shlomo Dado, S. Levegrün, G. T. Zorn, T. W. Pritchard, Georges Azuelos, H. M. Bosch, Wolfram Dietrich Zeuner, C. Moisan, J. R. Carter, O. Ganel, P. W. Jeffreys, P. Igo-Kemenes, G. Maringer, G. N. Patrick, K. W. Bell, J. P. Walker, C. Ho, X. C. Lou, Gideon Bella, D. Hochman, N. J. Thackray, H. J. Burckhart, Jacqueline Batley, M. W. Redmond, A. M. Lee, P. G. Murphy, A. J. Martin, Max Weber, H. Jeremie, K. Stephens, A. Rollnik, D. E. Klem, Kiyotomo Kawagoe, R. F. McGowan, J. C. Hill, Giora Mikenberg, J. R. McNutt, B. C. Shen, C. Fukunaga, A. Beck, M. A. Whalley, K. Riles, R. E. Hughes-Jones, U. Maur, R. Van Kooten, E. K. U. Gross, P. Teixeira-Dias, E. Heflin, A. Gaidot, Erez Etzion, M. Kuwano, W. G. Scott, M. Sproston, G. Eckerlin, Gareth J. Barker, R. M. Brown, Lorne Levinson, A. P. Wagner, P. Routenburg, A. Dieckmann, V. Gibson, John Baines, R. Kowalewski, M. J. Losty, M. F. Turner, P. Poffenberger, N. I. Geddes, Shlomit Tarem, P. A. Elcombe, Silvia Arcelli, J. L. Pinfold, A. Buijs, M. H. Lehto, H. O. Ogren, Christoph Geich-Gimbel, J. P. Martin, M. Sasaki, S. De Jong, B. W. Kennedy, D. L. Rees, J. Becker, B. Poli, S. Rossberg, C. J. Oram, D. R. Ward, P. F. Harrison, Stephen Lloyd, J. M. Roney, R. Yaari, S. Bethke, C. K. Hargrove, M. M. Deninno, H. M. Fischer, P. Debu, J. Mildenberger, Harold Nguyen, R. P. Middleton, Marco Cuffiani, J. Kroll, A. Michelini, J. D. Hobbs, F. X. Gentit, N. Wermes, G. G. Hanson, J. E. Conboy, M. Ogg, Ehud Duchovni, R. Shypit, S. A. Robins, D. E. Plane, Stephen Hillier, Michael Dittmar, E.J. Prebys, G. M. Dallavalle, A. Pouladdej, H. Ihssen, B. P. O'Neill, G. Yekutieli, M. S. Dixit, Frans Meijers, Alan Watson, D. J.P. Dumas, J. Hagemann, S. W. Gensler, J. Goldberg, B. Nellen, P. Leblanc, O. Schaile, D. C. Imrie, A. A. Carter, M. J. Goodrick, T. Kobayashi, M. Hansroul, S. W. O'Neale, Peter R Hobson, I. Cohen, S. J. Pawley, Phillip Allport, Claus Kleinwort, L. Köpke, R. J. Homer, S. Wotton, Margret Fincke-Keeler, G. P. Siroli, G. W. Wilson, M. Hauschild, P. S. Wells, D. R. Rust, P. Paschievici, C. J. Virtue, P. Pfister, Gideon Alexander, J. C. Armitage, M. Coupland, Paolo Capiluppi, P. Schenk, P. Lennert, S. Schreiber, M. Weymann, T. J. McMahon, Richard Keeler, C. Wahl, C. P. Howarth, J. E. Pilcher, R. K. Carnegie, H. E. Stier, R. Sobie, N. K. Watson, Claude Leroy, M. W. Moss, J. A. Wilson, J. P. Pansart, P. M. Hattersley, Sachio Komamiya, P. G. Estabrooks, W. Schappert, T. P. Kokott, Rene Brun, J. Banks, P. M. Watkins, S. Weisz, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, I. Wingerter, J. von Krogh, P. Ashton, Dave Robinson, H. Mes, I. P. Duerdoth, L. Janissen, C. Milstene, F. Odorici, Andris Skuja, Tetsuro Mashimo, W. Gorn, G. A. Bahan, M. Jobes, U. Binder, P. Scharff-Hansen, W. J. Larson, J. W. Gary, A. M. Smith, G. Vasseur, B. Lorazo, B. B. Brabson, D. G. Fong, J. Gascon, H. von der Schmitt, Marcello Mannelli, H. Takeda, F. G. Oakham, J. D. Gillies, R. J. Barlow, D. J. Miller, F. Lamarche, R. J. Hemingway, P. Jovanovic, Austin Ball, D. Menszner, and Alessandro Montanari
Subjects: Physics, Particle physics, Muon, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Electroweak interaction, Weinberg angle, Standard Model, Nuclear physics, High Energy Physics::Experiment, Engineering (miscellaneous), Pseudovector, Boson, Lepton
Abstract: We report on an improved measurement of the mass of theZ0 boson, its total width and its partial decay widths into hadrons and leptons, as well as the effective axial vector and vector couplings to charged leptons. These measurements are based on a data set of approximately 160 000 hadronicZ0 decays and 18 000 decays into electrons, muons and taus, recorded by the OPAL experiment at centre of mass energies near the mass of theZ0. The total width and the partial widths to visible final states, derived from the measured cross sections, are used to extract the invisible width. The effective couplings of theZ0 to charged leptons are studied using measurements of the lepton pair cross sections and forward-backward asymmetries at the different centre of mass energy points of theZ0 scan. The implications of our results in the context of the Standard Model are discussed.
Published: 1991

41. A study of - in Z0 decays

Author: Gideon Bella, H. J. Burckhart, Jacqueline Batley, M. Jobes, F. Odorici, R. Mir, U. Binder, H. Oh, H. O. Ogren, Michael Dittmar, C. M. Hawkes, M. Cooper, Daniel Lellouch, F. S. Merritt, G. Yekutieli, R. F. McGowan, Christoph Geich-Gimbel, Silvia Arcelli, M. M. Deninno, Tohru Takeshita, P. Scharff-Hansen, J. Kroll, F. X. Gentit, J. E. Conboy, Paul Kyberd, M. Ogg, R. Shypit, Takehiko Mori, T. Mouthuy, F. K. Loebinger, M. W. Moss, P. Igo-Kemenes, A. Pouladdej, G. Maringer, M. J. Oreglia, H. Jeremie, C. Moisan, J. P. Walker, F. Lamarche, R. E. Hughes-Jones, N. C. Wood, U. Maur, W. J. Larson, J. D. Hobbs, Georges Azuelos, P. M. Hattersley, H. Mes, M. W. Redmond, R. J. Hemingway, I. P. Duerdoth, R. Van Kooten, G. G. Hanson, P. Singh, J. W. Gary, A. Rollnik, K. W. Bell, P. Teixeira-Dias, G. A. Snow, C. P. Ward, A. A. Carter, G. Giacomelli, Max Weber, P. E.L. Clarke, M. Sprotson, J. R. Carter, A. M. Rossi, K. J. Anderson, Misao Sasaki, T. Behnke, R. W. L. Jones, M. H. Lehto, L. Janissen, B. C. Shen, P. Jovanovic, A. M. Smith, G. N. Patrick, E.J. Prebys, Austin Ball, Kiyotomo Kawagoe, T. Tsukamoto, D. E. Klem, S. Levegrün, D. Menszner, R. Sobie, G. Vasseur, B. Lorazo, S. Wotton, P. Le Du, W. G. Scott, M. S. Dixit, Frans Meijers, G. Beaudoin, M. Jimack, John Allison, H. Kreutzmann, B. Panzer-Steindel, D. Hochman, N. J. Thackray, I. J. Bloodworth, A. Simon, Otmar Biebel, E. K. U. Gross, A. P. Wagner, Alessandro Montanari, Gunter Quast, M. Weymann, K. Stephens, J. M. Roney, N. I. Geddes, R. Yaari, D. G. Charlton, J. R. McNutt, A. Gaidot, M. Couch, M. F. Turner, M. Kuwano, R. Kowalewski, M. Geerts, J. P. Martin, S. Bethke, B. B. Brabson, Shlomo Dado, C. Fukunaga, R. Humbert, Marco Cuffiani, M. Settles, H. E. Stier, John Hill, B. Poli, D. G. Fong, J. Gascon, X. C. Lou, S. De Jong, H. von der Schmitt, S. Schreiber, J. T.M. Chrin, M. J. Losty, G. Duckeck, T. J. McMahon, J. D. Gillies, P. G. Estabrooks, R. G. Kellogg, P. Routenburg, P. G. Murphy, D. Strom, V. Gibson, B. P. O'Neill, J. Hart, H. M. Fischer, T. Kawamoto, A. Michelini, Giora Mikenberg, G. T. Zorn, John Baines, R. J. Barlow, A. Astbury, P. M. Watkins, P. Debu, G. W. Wilson, Marcello Mannelli, R. K. Carnegie, Stefano Marcellini, A. Dieckmann, S. Orito, John H. Schwarz, J. Hagemann, D. Karlen, J. A. Wilson, D. C. Imrie, Y. Yang, C. Y. Chang, M. Fincke-Keeler, H. M. Bosch, Wolfram Dietrich Zeuner, Andris Skuja, S. A. Robins, I. Wingerter, J. L. Pinfold, O. Ganel, Tetsuro Mashimo, J. G. Layter, P. Taras, A. J. Martin, D. R. Ward, C. J. Oram, P. F. Harrison, Mitsuaki Nozaki, K. Riles, G. P. Siroli, W. Schappert, W. Gorn, J. Mildenberger, S. Bougerolle, G. A. Bahan, W. J. Collins, Harold Nguyen, S. Sanghera, Stephen Lloyd, J. M. Lorah, Erez Etzion, D. E. Plane, G. D. Lafferty, Gareth J. Barker, C. K. Hargrove, B. Holl, D. A. Hinshaw, Shlomit Tarem, W. Mohr, P. Pfister, Stephen Hillier, G. M. Dallavalle, G. Eckerlin, T. J. Smith, Phillip Allport, P. A. Elcombe, S. Rossberg, T. W. Pritchard, H. Takeda, I. Zacharov, J. C. Armitage, R. P. Middleton, F. G. Oakham, Alan Watson, D. L. Rees, D. J.P. Dumas, J. Becker, P. Mättig, S. J. Pawley, Horst Breuker, G. J. VanDalen, B. Nellen, P. Leblanc, M. Hansroul, W. R. Gibson, C. Ho, Claus Kleinwort, L. Köpke, R. J. Homer, D. Axen, P. Schenk, A. D. Schaile, A. Beck, A. Jawahery, Gideon Alexander, Paolo Capiluppi, G. Tysarczyk-Niemeyer, E. Heflin, M. J. Goodrick, I. Cohen, R. M. Brown, Lorne Levinson, N. Wermes, B. W. Kennedy, Ehud Duchovni, D. R. Rust, H. Ihssen, S. W. Gensler, T. Kobayashi, P. Lennert, J. Banks, S. Weisz, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, J. von Krogh, Peter Sherwood, R. W. Springer, J. Ludwig, K. Runge, P. Bock, P. Ashton, Dave Robinson, Sachio Komamiya, V. H. Winterer, S. R. Hou, T. P. Kokott, Rene Brun, N. K. Watson, S. W. O'Neale, Peter R Hobson, M. Hauschild, P. Paschievici, P R Poffenberger, D. J. Miller, H. Przysiezniak, O. Runolfsson, C. Wahl, L. Lessard, Claudio Grandi, P. W. Jeffreys, P. S. Wells, A. M. Lee, C. J. Virtue, C. P. Howarth, Terry Richard Wyatt, J. E. Pilcher, M. Coupland, O. Schaile, M. A. Whalley, A. Buijs, Richard Keeler, Claude Leroy, J. P. Pansart, and C. Milstene
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Meson, Branching fraction, High Energy Physics::Lattice, Electron–positron annihilation, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, Elementary particle, Nuclear physics, Pair production, Pion, High Energy Physics::Experiment, Nuclear Experiment
Abstract: In this paper an investigation of the production of D ∗ ± mesons produced in e + e − collisions at energies around the Z 0 pole is presented. Based on 115 D ∗ ± mesons with x D∗  2E D ∗ /E cm > 0.2 the properties of D ∗ mesons produced in the reaction Z 0 → c c are studied. Fixing the yield and the fragmentation function of bottom quarks to the values obtained at LEP using lepton tags, and average energy fraction of the D ∗ ± mesons from primary charmed quarks of 〈x c → D ∗ 〉 = 0.52 ± 0.03 +- 0.01 is found and Γ z 0 →c c = (323 ± 61 ± 35) MeV is determined. The first error is the combined statistical and systematic error from this experiment, and the second the total error from other sources.
Published: 1991

42. A measurement of energy correlations and a determination of αs(M2Z) e+e- annihilations at √s=91 GeV

Author: F. X. Gentit, F. Odorici, H. Takeda, G. A. Snow, C. P. Ward, C. Y. Chang, M. S. Dixit, G. Mikenberg, G.W. Wilson, L. Janissen, R. Stroehmer, W. J. Collins, M. T. French, Mitsuaki Nozaki, Christoph Geich-Gimbel, P. Singh, Erez Etzion, B. J. Saunders, Gareth J. Barker, D. C. Imrie, T. W. Pritchard, P. Igo-Kemenes, S. Rossberg, Michael Dittmar, M. M. Deninno, M. J. Losty, R. W. L. Jones, R. P. Middleton, J. Kroll, G. Yekutieli, G. Maringer, T. Mashino, J. Goldberg, H. Jeremie, B. Nellen, Shlomo Dado, S. L. Lloyd, G. P. Siroli, P. Leblanc, P. Le Du, H. Kreutzmann, R. G. Kellogg, J. E. Conboy, R. E. Hughes-Jones, U. Maur, A. A. Carter, A. Jawahery, J.P. Pansart, N. K. Watson, P. G. Murphy, J. Grunhaus, M. Ogg, J. D. Gillies, M. J. Goodrick, Stefano Marcellini, T. J. Smith, H. Oh, I. Cohen, G. Tysarczyk-Niemeyer, D. G. Fong, V. Gibson, Kiyotomo Kawagoe, K. J. Anderson, A. Pouladdej, Peter Sherwood, Gideon Bella, J. Gascon, S. Wotton, N. C. Wood, H. J. Burckhart, P. Mättig, B. C. Shen, B. Wuensch, A. M. Rossi, J. M. Lorah, M. Weymann, G. D. Lafferty, Takashi Yoshida, R. W. Springer, A. P. Wagner, J. M. Roney, H. von der Schmitt, C. Fukunaga, D. E. Klem, G.T.J. Arnison, D. J. Miller, A. Buijs, J. Ludwig, K. Runge, P. Bock, Jacqueline Batley, A. A. Macbeth, M. Hauschild, Makoto Minowa, W. Mohr, I. J. Bloodworth, T. Tsukamoto, H. E. Stier, G. Knop, J. Mildenberger, Harold Nguyen, J. Hagemann, M. F. Turner, P. G. Estabrooks, S. Schreiber, T. J. McMahon, R. K. Carnegie, N. I. Geddes, M. Jimack, D. Karlen, O. Ganel, A. J. Martin, F. Lamarche, P. Lennert, Marcello Mannelli, T. P. Kokott, Rene Brun, C. N. P. Gee, J. A. Wilson, B. Poli, F. S. Merritt, C. M. Hawkes, J. Allison, Daniel Lellouch, P. M. Watkins, M. Jobes, U. Binder, W. J. Murray, R. J. Hemingway, R. Kowalewski, H. M. Fischer, D. Granite, Takehiko Mori, J. Ma, W. Schappert, D. Strom, P. Scharff-Hansen, Paul Kyberd, F. K. Loebinger, G. T. Zorn, P. Jovanovic, A. Michelini, I. Wingerter, W. J. Larson, J. D. Hobbs, M. Sasaki, E. K. U. Gross, A. Gaidot, P. E.L. Clarke, M. Kuwano, T. Behnke, Austin Ball, D. Menszner, M. W. Redmond, Wolfram Dietrich Zeuner, K. Riles, J. L. Pinfold, J. W. Gary, S. A. Robins, M. Sproston, A. Rollnik, M. W. Moss, M. Z. Akrawy, I. Harrus, A. M. Smith, P. M. Hattersley, M. J. Oreglia, M. H. Lehto, P. Routenburg, J. R. Carter, Alessandro Montanari, A. Dieckmann, H. Mes, G. Vasseur, J. von Krogh, J. Raab, B. Lorazo, F. G. Oakham, Andris Skuja, P. A. Elcombe, P. Ashton, B. Holl, S. W. O'Neale, Peter R Hobson, H. El Mamouni, Tohru Takeshita, R. Yaari, S. Bethke, Marco Cuffiani, D. L. Rees, A. Shapira, J. Becker, A. D. Schaile, I. P. Duerdoth, Georges Azuelos, S. J. Pawley, Claus Kleinwort, L. Köpke, Horst Breuker, G. N. Patrick, A. Simon, Otmar Biebel, K. W. Bell, Max Weber, O. Schaile, W. Gorn, P. S. Wells, J. C. Hill, G. Giacomelli, C. J. Virtue, Terry Richard Wyatt, D. G. Charlton, A. T. Watson, M. Coupland, E.J. Prebys, J. Banks, Gunter Quast, M. Couch, S. Weisz, R. D. Heuer, Fabrizio Fabbri, D. Van den plas, R. Humbert, Frans Meijers, J. T.M. Chrin, T. Kawamoto, V. H. Winterer, S. Orito, John H. Schwarz, S. R. Hou, J. G. Layter, C. Wahl, C. P. Howarth, J. E. Pilcher, N. Wermes, C. K. Hargrove, Ehud Duchovni, R. A. Sansum, H. Ihssen, S. Sanghera, S. W. Gensler, Phillip Allport, J. P. Martin, C. M. Roach, B.P. O'Neil, D. E. Plane, Stephen Hillier, G. M. Dallavalle, P. Farthouat, Gideon Alexander, Paolo Capiluppi, D. Hochman, N. J. Thackray, J. Hart, G. J. VanDalen, R. J. Barlow, P. Pfister, Y. Yang, D. J.P. Dumas, P. W. Jeffreys, J. C. Armitage, T. Kobayashi, A. M. Lee, K. Stephens, J. R. McNutt, P. Debu, M. Hansroul, R. J. Homer, John Baines, M. Regimbald, O. Runolfsson, A. J.P. O'Dowd, J. P. Walker, D. R. Ward, W. R. Gibson, C. Ho, A. Beck, E. Heflin, R. M. Brown, Lorne Levinson, L. Lessard, B. W. Kennedy, C. Milstene, and H. Hagedorn
Subjects: Coupling constant, Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Electron–positron annihilation, Hadron, Nuclear physics, Renormalization, Particle decay, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Boson
Abstract: From an analysis of multi-hadron events from Z 0 decays, values of the strong coupling constant α s ( M 2 Z 0 )=0.131±0.006 (exp)±0.002(theor.) and α s ( M z 0 2 ) = −0.009 +0.007 (exp.) −0.002 +0.006 (theor.) are derived from the energy-energy correlation distribution and its asymmetry, respectively, assuming the QCD renormalization scale μ = M Z 0 . The theoretical error accounts for differences between O ( α 2 s ) calculations. A two parameter fit Λ MS and the renormalization scale μ leads to Λ MS =216±85 MeV and μ 2 s =0.027±0.013 or to α s ( M 2 Z 0 )=0.117 +0.006 −0.008 (exp.) for the energy-energy correlation distribution. The energy-energy correlation asymmetry distribution is insensitive to a scale change: thus the α s value quoted above for this variable includes the theoretical uncertainty associated with the renormalization scale.
Published: 1990

43. Measurements of the decay of the Z0 into lepton pairs

Author: J. Waterhouse, B. J. Saunders, Phillip Allport, B. C. Shen, H. M. Fischer, T. J. McMahon, J. C. Armitage, E. J. Spreadbury, D. Duchesneau, J. A. Wilson, P. Grosse-Wiesmann, A. J.P. O'Dowd, I. Cohen, P. Le Du, D. Granite, C. Milstene, R. W.L. Jones, D. G. Fong, E. Jin, H. von der Schmitt, D. J.P. Dumas, S. R. Hou, Gideon Bella, J. von Krogh, J. Raab, G. A. Snow, C. P. Ward, G. Knop, Despina Hatzifotiadou, H. J. Burckhart, H. Jeremie, H. Kreutzmann, Jacqueline Batley, C. Geich-Gimbel, P. Ashton, R. M. Brown, G. T.J. Arnison, Marcello Mannelli, H. Wang, Andris Skuja, F. S. Merritt, G. D. Lafferty, Michael Dittmar, Kiyotomo Kawagoe, Tetsuro Mashimo, J. L. Pinfold, Gunter Quast, C. J. Virtue, J. P. Martin, F. Roehner, P. Kyberd, Paolo Capiluppi, J. M. Roney, Tohru Takeshita, K. W. Bell, P. Bock, D. G. Charlton, M. Couch, A. M. Rossi, D. E. Plane, W. Gorn, P. A. Elcombe, G. Yekutieli, W. R. Gibson, T. P. Kokott, B. Holl, Stephen Hillier, J. Heintze, P. G. Estabrooks, M. Jobes, D. Hochman, I. P. Duerdoth, D. L. Rees, P. Routenburg, R. Kowalewski, S. Schreiber, J. T.M. Chrin, C. K. Hargrove, C. M. Roach, B. P. O'Neill, D. Karlen, N. Lupu, A. Dieckmann, C. Fukunaga, P. Scharff-Hansen, W. J. Larson, A. Buijs, G. J. VanDalen, H. Boerner, G. P. Siroli, A. Jawahery, Peter Sherwood, T. Kawamoto, M. Jimack, R. W. Springer, M. Coupland, N. K. Watson, P. G. Murphy, U. Maur, C. N.P. Gee, A. M. Smith, H. El Mamouni, D. Strom, Horst Breuker, G. T. Zorn, P. M. Watkins, P. Igo-Kemenes, Wolfram Dietrich Zeuner, F. Beck, R. Ströhmer, A. Wagner, Rolf-Dieter Heuer, T. Tsukamoto, G. N. Patrick, B. Poli, M. Sproston, A. Rollnik, S. Orito, S. Zylberajch, S. Sanghera, C. Wahl, M. F. Turner, H. Oh, O. Runolfsson, P. Lennert, J. M. Lorah, H. Yamashita, B. Lorazo, M. Z. Akrawy, Makoto Minowa, H. E. Stier, T. W. Pritchard, M. Weymann, M. W. Moss, W. Mohr, M. M.B. Lasota, P. S. Hinde, M. Regimbald, P. M. Hattersley, A. Possoz, H. Takeda, I. Wingerter, C. Beard, C. Ho, Marco Cuffiani, J. W. Gary, E. Heflin, S. Bethke, B. W. Kennedy, J. C. Hill, Misao Sasaki, M. J. Oreglia, N. I. Geddes, G. J. Barker, N. C. Wood, M. M. Deninno, R. J. Barlow, A. A. Carter, D. J. Miller, J. Schwarz, J. Kroll, M. Ogg, J. R. Carter, R. Yaari, J. Ma, W. J. Murray, L. Levinson, P. Jovanovic, S. Wotton, Austin Ball, F. K. Loebinger, F. X. Gentit, J. E. Conboy, A. C. McPherson, W. Schappert, M. S. Dixit, Alessandro Montanari, B. Nellen, J. Banks, G. Azuelos, H. Mes, A. Simon, S. W. Gensler, R. E. Hughes-Jones, A. Shapira, Aldo Michelini, E. Gross, Fabrizio Fabbri, D. Van den plas, G. Tysarczyk, O. Ganel, K. Riles, M. W. Redmond, S. Weisz, P. Farthouat, A. Pouladdej, G. Mikenberg, T. Kobayashi, R. K. Carnegie, O. Schaile, D. C. Imrie, J. Ludwig, C. P. Howarth, J. Grunhaus, Terry Richard Wyatt, F. G. Oakham, J. E. Pilcher, E. Duchovni, M. Hansroul, A. A. Macbeth, G. W. Wilson, P. W. Jeffreys, S. J. Pawley, G. Maringer, Claus Kleinwort, L. Köpke, Masatoshi Koshiba, J. Hart, M. Hauschild, D. E. Klem, Harold Nguyen, V. H. Winterer, P. Leblanc, R. J. Homer, L. Lessard, K. J. Anderson, Y. Yang, Achim Müller, O. Biebel, John Allison, C. Y. Chang, A. D. Schaile, Stephen Lloyd, R. G. Kellogg, B. Gandois, Mitsuaki Nozaki, M. Weber, Stefano Marcellini, K. Stephens, Masatoshi Imori, John Baines, G. Bavaria, F. Odorici, D. R. Ward, F. Lamarche, M. T. French, O. W. Davies, M. J. Losty, Richard J Hemingway, S. W. O'Neale, Peter R Hobson, A. T. Watson, Rene Brun, J. Hagemann, I. J. Bloodworth, James D Gillies, A. Perez, R. A. Sansum, G. M. Dallavalle, J. Goldberg, T. J. Smith, P. Mättig, C. M. Hawkes, Daniel Lellouch, Takehiko Mori, R. P. Middleton, D. Menszner, M. J. Goodrick, J. G. Layter, J. D. Hobbs, G. Alexander, G. Giacomelli, S. Dado, H. Hagedorn, Frans Meijers, K. Runge, B. Wuensch, and N. Wermes
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Standard Model (mathematical formulation), Basis (linear algebra), Electron–positron annihilation, Hadron, Particle Physics - Experiment, Lepton
Abstract: We report on a measurement of the processes e+e−→e+e−, e+e−→μ+μ−, and e+e−→τ+τ− near the Z0 pole. On the basis of 163 e+e−, 101 μ+μ− and 87 τ+τ− events we obtain Γee=89±4±4 MeV, Γμμ=85±9±6 MeV and Γττ=87±10±8 MeV, compatible with the standard model. Combining these with our previous results on hadronic Z0 decays, we find a hadronic width Γhad=1787±81±90 MeV and an invisible width Γinv=552±85±71 MeV.
Published: 1990

44. High prevalence of adrenal suppression during acute illness in hospitalized patients receiving megestrol acetate

Author: A. R. Chidakel, P. Homel, S. B. Zweig, Jonathan Schlosser, A. M. Fleckman, and J. W. Schappert
Subjects: Male, medicine.medical_specialty, Cortisol awakening response, Hydrocortisone, Endocrinology, Diabetes and Metabolism, Appetite Stimulants, Endocrinology, Internal medicine, medicine, Adrenal insufficiency, Endocrine system, Humans, Wasting, Aged, Aged, 80 and over, business.industry, Wasting Syndrome, Endometrial cancer, Megestrol Acetate, Middle Aged, medicine.disease, Cross-Sectional Studies, Megestrol acetate, Female, medicine.symptom, business, Weight gain, Glucocorticoid, medicine.drug, Adrenal Insufficiency
Abstract: Introduction: Megestrol acetate (MA) is a progestational agent used for palliation of breast and endometrial cancer. The drug promotes weight gain via appetite stimulation. This property has led to widespread use in patients with wasting illnesses. Increasing numbers of reports suggest glucocorticoid activity. Objective: Unrecognized adrenal suppression may result from MA use. This is the first study to examine the prevalence of adrenal suppression in hospitalized patients treated with MA. Subjects and design: This is a cross-sectional study of hospitalized patients receiving MA compared to control subjects. Morning cortisol levels, endocrine signs and symptoms, and duration of MA therapy were evaluated in 28 hospitalized medical patients treated with MA, and 21 control patients admitted to the same hospital service during the study period. Results: Median cortisol levels were significantly lower in patients using MA vs controls (160 vs 386 nmol/l, p=0.003). Forty-three percent of subjects on MA demonstrated morning cortisol levels below the normal range (138-690 nmol/l), compared with 10% of controls (p=0.013). Ninety-three percent of subjects taking MA had morning cortisol levels below the level that excludes adrenal insufficiency in hospitalized patients (497 nmol/l) vs 71% of controls (p=0.06). Conclusions: MA use is associated with significant adrenal suppression in acutely ill individuals. This should alert physicians to the possibility of adrenal insufficiency and the need to assess for signs or symptoms of adrenal insufficiency, and mandates a low threshold for testing adrenal function in hospitalized patients taking MA.
Published: 2006

45. Digital down conversion technology for tevatron beam line tuner at FNAL

Author: J. Sebek, M. Ross, T. Straumann, V. Scarpine, W. Schappert, and E. Lorman
Subjects: Physics, Nuclear physics, Time of arrival, Luminosity (scattering theory), law, Tevatron, Physics::Accelerator Physics, Particle accelerator, Tuner, Fermilab, Collider, Beam (structure), law.invention
Abstract: Fermilab is presently in Run II collider operations and is developing instrumentation to improve luminosity. Improving the orbit matching between accelerator components using a Beam Line Tuner (BLT) can improve the luminosity. Digital Down Conversion (DDC) has been proposed as a method for making more accurate beam position measurements. Fermilab has implemented a BLT system using a DDC technique to measure orbit oscillations during injections from the Main Injector to the Tevatron. The output of a fast ADC is down-converted and filtered in software. The system measures the x and y positions, the intensity, and the time of arrival for each proton or antiproton bunch, on a turn-by-turn basis, during the first 1024 turns immediately following injection. We present results showing position, intensity, and time of arrival for both injected and coasting beam. Initial results indicate a position resolution of /spl sim/20 to 40 microns and a phase resolution of /spl sim/25 ps.
Published: 2004

46. Bunch-by-bunch digital dampers for the Fermilab main injector and recycler

Author: A. Seminov, W. Ashmanskas, G. W. Foster, S. Hansen, D. Wildman, D. Nicklaus, and W. Schappert
Subjects: Engineering, business.industry, Firmware, Amplifier, Electrical engineering, computer.software_genre, Damper, Transverse plane, Gate array, Electronic engineering, Physics::Accelerator Physics, Fermilab, business, Field-programmable gate array, computer, Beam (structure)
Abstract: A digital transverse and longitudinal bunch-by-bunch damper has been prototyped and tested. The damper is based on immediate 14-bit digitization at 212 MHz (4x the 53 MHz RF bunch frequency), digital pipelined processing in field-programmable gate array (FPGA) logic, and a digitally synthesized damping kick driven by a 212 MHz DAC. A single board performs all calculations for both transverse and longitudinal damping, as well as providing extensive diagnostic read out, and automatically switching between the variety of beam types present. Initial prototyping was carried out by customizing firmware on a commercial board, and has successfully demonstrated bunch-by-bunch transverse damping, antidamping, and pinging. Longitudinal damping uses identical firmware with different FIR coefficients, and will be beam tested when cavities and power amplifiers are installed in the Main Injector summer 2003. A second generation board, in which damping calculations for all 3 coordinates are performed in a single large FPGA is in fabrication. Several other applications are being considered for this board, including implementation of an entire Low-Level RF system on a single board.
Published: 2004

47. Test of an optical transition radiation detector for high-intensity proton beams at FNAL

Author: W. Schappert, Alex H. Lumpkin, G.R. Tassotto, and V.E. Scarpine
Subjects: Physics, medicine.medical_specialty, Proton, Physics::Instrumentation and Detectors, business.industry, Optical transition, Detector, Radiation, Particle detector, Optics, Antiproton, medicine, Physics::Accelerator Physics, High Energy Physics::Experiment, Medical physics, business, Beam (structure), Fermi Gamma-ray Space Telescope
Abstract: Initial results are presented of a prototype optical transition radiation (OTR) detector under development at Fermi National Accelerator Laboratory (FNAL). The purpose of this prototype detector is to evaluate the feasibility of using OTR imaging of proton (or antiproton) beams in transport lines for beam position and shape measurements. A secondary purpose is to develop experience in designing, constructing and operating a camera and optics system in high radiation environments. Measurements are made of 120 GeV proton beams with up to 4.7 /spl times/ 10/sup 12/ particle intensities. Data are presented of OTR with titanium and aluminum foils.
Published: 2003

48. Studies of charged particle multiplicity in b quark events

Author: D. E. Plane, Otmar Biebel, G. E. Richards, D. G. Charlton, D. L. Wagner, Sachio Komamiya, E. Ros, P. Bentkowski, G. M. Dallavalle, H. Deng, R. Humbert, H. M. Fischer, Tara Shears, Gideon Bella, H. J. Burckhart, T. P. Kokott, A. Luig, Alan Watson, D. J.P. Dumas, Jacqueline Batley, A. Michelini, A. C. Janissen, Norbert Wermes, Sherry Towers, T. Kawamoto, J. Goldberg, M. J. Pearce, Horst Breuker, B. Nellen, S. Orito, P. Igo-Kemenes, H. Jeremie, A. Jawahery, P. Leblanc, M. Rosvick, J. Hart, Andris Skuja, S. A. Robins, R. E. Hughes-Jones, U. Maur, Gregor Herten, C. Wahl, K. Stephens, B. Wilkens, Tetsuro Mashimo, H. G. Evans, J. D. Gillies, D. Pitman, M. H. Lehto, A. Astbury, E. do Couto e Silva, J. Steuerer, Ehud Duchovni, M. J. Goodrick, Margret Fincke-Keeler, I. Cohen, J. R. McNutt, P. Pfister, M. Hansroul, A. Yeaman, J. E. Pilcher, U. Müller, A. J. Martin, D. M. Gingrich, R. J. Barlow, Madjid Boutemeur, M. Jimack, H. Ihssen, C. H. Shepherd-Themistocleous, D. J. Miller, C. Sbarra, F. C. Grant, D. A. Hinshaw, W. Gorn, R. J. Homer, Kiyotomo Kawagoe, N. K. Watson, V. H. Winterer, V. Gibson, G. Quast, F. S. Merritt, H. Mes, C. Moisan, G. A. Beck, M. A. Whalley, John Baines, Achim Stahl, P. Teixeira-Dias, R. Mir, Michael Dittmar, G. Yekutieli, P. Berlich, B. Schmitt, R.J. Akers, S. W. Gensler, R. Yaari, S. Bethke, Marco Cuffiani, N. I. Geddes, D. R. Ward, G. Transtromer, B. Fabbro, J. A. McKenna, O. Schaile, I. P. Duerdoth, T. Behnke, S. J. Hillier, T. Kobayashi, C. K. Hargrove, Matthias Schröder, A. Buijs, Paul Kyberd, F. K. Loebinger, D. M. Strom, C. Stegmann, P. Weber, A. A. Carter, Roger Jones, R. Van Kooten, B. Panzer-Steindel, P. G. Estabrooks, M. G. Rison, Erez Etzion, B. Boden, Stefan Kluth, Shlomit Tarem, J. Banks, N. J. Tresilian, R. D. Heuer, Fabrizio Fabbri, H. Lafoux, B. Poli, D. Van den plas, M. J. Oreglia, S. L. Chu, S. Barnett, P. M. Watkins, N. Paz-Jaoshvili, M. Morii, D. Hochman, R. Bartoldus, James Pinfold, H. O. Ogren, Christoph Geich-Gimbel, A. Rollnik, R. Giacomelli, S. Rossberg, C. J. Oram, H. Przysiezniak, D. G. Fong, C. Jui, J. von Krogh, M. Fierro, D. R. Rust, Peter R Hobson, M. Yurko, P. Routenburg, J. Gascon, J. Kroll, R. Lahmann, R. P. Middleton, J. M. Lorah, H. von der Schmitt, John Hobbs, W. Mohr, J. C. Clayton, P. W. Jeffreys, D. C. Imrie, M. Jones, M. Hauschild, Richard Keeler, F. X. Gentit, J. Mildenberger, Harold Nguyen, J. R. Carter, R. Kowalewski, J. E. Conboy, G. N. Patrick, A. M. Lee, Dave Robinson, Gunter Wolf, G. Duckeck, R. Ströhmer, Gordon H. Hanson, C. Markus, P. Paschievici, P. Bright-Thomas, J. W. Gary, L. A. del Pozo, A. M. Rossi, Silvia Arcelli, T. Tsukamoto, T. J. McMahon, G. T. Zorn, M. W. Redmond, S. Wotton, Marcello Mannelli, J. E. Duboscq, G. P. Siroli, J. King, J. Schwiening, R. K. Carnegie, P. Scharff-Hansen, Christoph Schwick, Claude Leroy, J. Lauber, John Allison, J. P. Pansart, A. Skillman, M. A. Thomson, H. M. Bosch, Wolfram Dietrich Zeuner, E. Lefebvre, J. A. Wilson, Gideon Alexander, Paolo Capiluppi, F. Odorici, R. G. Kellogg, T. Hilse, W. Schappert, D. S. Koetke, O. Runolfsson, A. M. Smith, D. Axen, Stefano Marcellini, P. S. Wells, G. Vasseur, C. Beeston, B. Lorazo, A. Gaidot, J. M. Roney, James Letts, Claudio Grandi, Randall Sobie, G. D. Lafferty, H. Takeda, Terry Richard Wyatt, T. Wlodek, F. G. Oakham, Peter Sherwood, M. Sproston, M. Coupland, R. W. Springer, Alexander Wagner, P. F. Harrison, J. Hagemann, J. Ludwig, G. J. Van Dalen, P. M. Hattersley, Stephen Lloyd, M. Tecchio, K. Runge, P. Bock, Robert M Brown, T. W. Pritchard, N. Tesch, A. Dieckmann, P. A. Elcombe, R. J. Hemingway, P. Jovanovic, J. Becker, Austin Ball, D. Menszner, F. Scharf, Alessandro Montanari, W. R. Gibson, A. Beck, E. Heflin, Lorne Levinson, B. W. Kennedy, E. Torrente-Lujan, S. W. O'Neale, K. J. Anderson, C. Y. Chang, M. F. Turner, P. Poffenberger, G. Beaudoin, Shlomo Dado, X. C. Lou, Giora Mikenberg, B. C. Shen, A. K. Honma, W. G. Scott, G. A. Snow, C. P. Ward, D. L. Rees, M. J. Losty, Tohru Takeshita, Georges Azuelos, J. F. Kral, K. W. Bell, Max Weber, J. C. Hill, Misao Sasaki, T. J. Smith, P. Mättig, I. J. Bloodworth, M. Settles, M. Foucher, G. W. Wilson, D. Karlen, C. Burgard, C. M. Hawkes, M. Cooper, Daniel Lellouch, Takehiko Mori, P. E.L. Clarke, J. P. Martin, S. De Jong, J. G. Layter, G. Giacomelli, A. D. Schaile, P. Schenk, M. S. Dixit, and Frans Meijers
Subjects: Systematic error, Physics, Particle physics, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Elementary particle, Lambda, Bottom quark, Charged particle, Vertex (geometry), Nuclear physics, Multiplicity (chemistry), Engineering (miscellaneous), Particle Physics - Experiment
Abstract: Using the distance from the average primary vertex to reconstructed secondary vertices in jets, samples of events withb purity varying from about 13% to 89% have been selected. The charged particle multiplicity in the hemispheres opposite those containing these jets has been studied as a function of theb purity of the events. Extrapolating to 0% and 100%b purity, values of the hemisphere charged particle multiplicity inZ0→$b\bar b$ events and in non-$b\bar b$ events have been measured to be $$\begin{gathered} \bar n_b = 11.71 \pm 0.03 \pm 0.18 \pm 0.21, \hfill \\ \bar n_{udsc} = 10.32 \pm 0.01 \pm 0.07 \pm 0.19. \hfill \\ \end{gathered}$$ The first error is statistical, the second systematic and the third is a common systematic error.
Published: 1993

49. Improved measurements of the neutral current from hadron and lepton production at LEP

Author: Erez Etzion, Stefan Kluth, Shlomit Tarem, A. Astbury, Shlomo Dado, J. Steuerer, Andris Skuja, U. Müller, S. Rossberg, C. J. Oram, J. Allison, W. R. Gibson, A. J. Martin, G. Duckeck, R. Mir, Tohru Takeshita, R. P. Middleton, R. Ströhmer, Paul Kyberd, F. K. Loebinger, T. J. Smith, A. Rollnik, R. Giacomelli, Tetsuro Mashimo, X. C. Lou, Ehud Duchovni, Georges Azuelos, R. Bartoldus, A. Beck, J. Hart, P. A. Elcombe, F. C. Grant, M. A. Whalley, R. G. Kellogg, E. Heflin, C. Y. Chang, M. Jimack, T. Hilse, C. K. Hargrove, D. S. Koetke, Gunter Wolf, H. Ihssen, J. F. Kral, K. W. Bell, Max Weber, H. O. Ogren, Matthias Schröder, W. Gorn, D. Pitman, M. H. Lehto, Lorne Levinson, E. Lefebvre, Giora Mikenberg, Stefano Marcellini, M. F. Turner, P. Mättig, H. M. Bosch, Wolfram Dietrich Zeuner, James Letts, H. Lafoux, P. Igo-Kemenes, O. Runolfsson, S. W. Gensler, Christoph Geich-Gimbel, J. D. Gillies, J. C. Hill, N. Paz-Jaoshvili, B. W. Kennedy, M. J. Oreglia, E. Torrente-Lujan, J. Mildenberger, Gideon Bella, H. J. Burckhart, C. M. Hawkes, M. Cooper, Harold Nguyen, Gordon H. Hanson, Daniel Lellouch, S. J. Hillier, T. Kobayashi, J. Becker, A. Buijs, M. W. Redmond, R. Yaari, S. Bethke, C.J. Beeston, Jacqueline Batley, H. Jeremie, S. Wotton, Marco Cuffiani, B. C. Shen, R. E. Hughes-Jones, F. Odorici, D. M. Strom, C. Stegmann, Takehiko Mori, F. Scharf, Gregor Herten, G. J. VanDalen, James Pinfold, U. Maur, D. G. Fong, C. Wahl, Claudio Grandi, J. Kroll, D. J. Miller, D. M. Gingrich, A. K. Honma, J. Gascon, W. G. Scott, B. Wilkens, Tara Shears, A. Beaudoin, P. M. Hattersley, J. Goldberg, D. A. Hinshaw, D. E. Plane, H. von der Schmitt, R. Kowalewski, M. Morii, Peter R Hobson, F. X. Gentit, P. Bentkowski, J. E. Conboy, B. Nellen, S. L. Chu, V. Gibson, G. N. Patrick, A. Jawahery, M. J. Losty, P. Leblanc, J. E. Pilcher, G. M. Dallavalle, P. Berlich, J. W. Gary, P. Routenburg, M. J. Pearce, Horst Breuker, T. Behnke, M. Yurko, Margret Fincke-Keeler, R. Lahmann, P. W. Jeffreys, D. C. Imrie, E. do Couto e Silva, Otmar Biebel, G. E. Richards, Alan Watson, S. W. O'Neale, D. R. Rust, K. J. Anderson, G. A. Snow, D. J.P. Dumas, C. P. Ward, D. G. Charlton, D. L. Wagner, G. P. Siroli, Marcello Mannelli, J. E. Duboscq, J. Lauber, H. G. Evans, J. G. Layter, M. J. Goodrick, I. Cohen, M. Hauschild, J. King, I. J. Bloodworth, H. Deng, R. Humbert, P. S. Wells, J. M. Lorah, Christoph Schwick, Gideon Alexander, C. Markus, D. L. Rees, A. M. Lee, D. Axen, P. Bright-Thomas, Paolo Capiluppi, John Hobbs, H. Takeda, P. Poffenberger, P. Paschievici, M. Settles, W. Mohr, F. S. Merritt, A. Yeaman, M. Coupland, Peter Sherwood, N. K. Watson, Kiyotomo Kawagoe, F. G. Oakham, Norbert Wermes, M. Foucher, Sherry Towers, T. Kawamoto, R. W. Springer, Alexander Wagner, Sachio Komamiya, J. Hagemann, J. Ludwig, N. I. Geddes, K. Runge, B. Fabbro, B. Panzer-Steindel, R. J. Hemingway, R.J. Akers, P. Weber, M. Jones, Richard Keeler, G. W. Wilson, S. Orito, M. Rosvick, A. Skillman, M. A. Thomson, P. Scharff-Hansen, P. F. Harrison, D. Karlen, P. Bock, C. Burgard, E. Ros, A. Gaidot, P. Jovanovic, O. Schaile, J. A. McKenna, T. Wlodek, M. Sproston, Stephen Lloyd, M. Tecchio, Robert M Brown, T. P. Kokott, A. Luig, J. Banks, T. R. Wyatt, N. J. Tresilian, Austin Ball, D. Menszner, B. Boden, Claude Leroy, J. P. Pansart, N. Tesch, A. Dieckmann, R. J. Barlow, R. D. Heuer, H. Mes, I. P. Duerdoth, H. Przysiezniak, M. Fierro, Fabrizio Fabbri, D. Van den plas, A. M. Smith, Alessandro Montanari, B. Poli, Silvia Arcelli, G. Vasseur, B. Lorazo, P. Pfister, J. M. Roney, G. D. Lafferty, Madjid Boutemeur, P. G. Estabrooks, G. Giacomelli, G. T. Zorn, P. Schenk, P. M. Watkins, M. S. Dixit, Frans Meijers, P. E.L. Clarke, A. M. Rossi, T. Tsukamoto, J. P. Martin, H. M. Fischer, M. Hansroul, M. Sasaki, S. De Jong, A. Michelini, A. C. Janissen, C. H. Shepherd-Themistocleous, R. J. Homer, S. A. Robins, C. Moisan, G. A. Beck, Achim Stahl, P. Teixeira-Dias, B. Schmitt, J. R. Carter, A. D. Schaile, V. H. Winterer, Randall Sobie, T. W. Pritchard, C. Jui, J. C. Clayton, S. Barnett, T. J. McMahon, D. Hochman, J. Schwiening, R. K. Carnegie, J. A. Wilson, W. Schappert, K. Stephens, J. R. McNutt, C. Sbarra, Michael Dittmar, G. Yekutieli, A. A. Carter, Roger Jones, R. Van Kooten, G. Quast, John Baines, M. G. Rison, J. von Krogh, Dave Robinson, D. R. Ward, G. Transtromer, and L. A. del Pozo
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Neutral current, Electron–positron annihilation, Physics beyond the Standard Model, High Energy Physics::Phenomenology, Hadron, Universality (dynamical systems), Nuclear physics, High Energy Physics::Experiment, Born approximation, Engineering (miscellaneous), Particle Physics - Experiment, Lepton
Abstract: We present an update with increased statistics to our published analysis of hadronic and leptonic cross sections and of the leptonic forward-backward asymmetries ine + e − collisions. The published results were based on a total 454 000 hadronic and 58 000 leptonic events. This analysis adds 733 000 hadronic and 88 000 leptonic events recorded at theZ 0 peak in 1992 by the OPAL experiment at LEP. A model independent analysis ofZ 0 parameters based on an extension of the improved Born approximation leads to tests of lepton universality and gives an interpretation of the results within the Standard Model framework. We also present a model independent test for new physics.
Published: 1993

50. A Determination of $\ alpha_{s}(M_{Z0})$ at LEP using Resummed QCD Calculations

Author: Gideon Bella, J. D. Gillies, A. Simon, H. J. Burckhart, Jacqueline Batley, P. A. Elcombe, Otmar Biebel, G. E. Richards, D. J. Miller, D. G. Charlton, D. L. Wagner, Phillip Allport, James Pinfold, M. Manelli, M. Morri, D. G. Fong, I. J. Bloodworth, H. Deng, R. Humbert, J. Gascon, H. von der Schmitt, F. Lamarche, R. J. Hemingway, P. Jovanovic, Austin Ball, D. Menszner, Alessandro Montanari, D. A. Hinshaw, F. G. Oakham, M. Yurko, M. Settles, P. E.L. Clarke, P. W. Jeffreys, Gideon Alexander, Paolo Capiluppi, T. Kobayashi, C. Jui, J. Steuerer, M. Foucher, Norbert Wermes, A. M. Lee, P. M. Hattersley, W. R. Gibson, J. E. Duboscq, G. W. Wilson, T. Kawamoto, J. M. Roney, H. Przysierzniak, D. Karlen, S. Wotton, P. Singh, Ehud Duchovni, R. Shypit, Andris Skuja, P. Igo-Kemenes, G. Maringer, P. Bright-Thomas, Silvia Arcelli, J. K. Becker, D. Axen, C. M. Hawkes, A. Jawahery, M. Cooper, Daniel Lellouch, R. W. L. Jones, H. Ihssen, Tetsuro Mashimo, A. Beck, H. Jeremie, Kiyotomo Kawagoe, S. W. O'Neale, G. Tysarczyk-Niemeyer, G. A. Snow, C. P. Ward, W. J. Collins, S. Orito, M. Rosvick, D. L. Rees, Takehiko Mori, Peter Sherwood, J. M. Lorah, T. Behnke, E. Heflin, S. W. Gensler, S. J. Hillier, C. J. Virtue, B. Panzer-Steindel, R. E. Hughes-Jones, U. Maur, M. A. Thomson, R. W. Springer, Alexander Wagner, J. Hagemann, J. Ludwig, G. J. Van Dalen, K. Runge, G. G. Hanson, P. Bock, W. Mohr, R. M. Brown, R. Mir, T. W. Pritchard, J. Goldberg, B. Nellen, Michael Dittmar, W. Gorn, Lorne Levinson, G. Giacomelli, R. Yaari, K. J. Anderson, P. Leblanc, P. S. Wells, V. Gibson, S. Bethke, Marco Cuffiani, Tohru Takeshita, G. Yekutieli, P. Schenk, E. do Couto e Silva, Shlomo Dado, G. A. Bahan, T. Hilse, S. Barnett, J. Allison, G. Duckeck, R. Ströhmer, M. Hansroul, P. Weber, P. F. Harrison, B. W. Kennedy, M. Jobes, U. Binder, O. Runolfsson, M. Hauschild, Gilles Beaudoin, A. D. Schaile, C. H. Shepherd-Themistocleous, P. D. Acton, M. S. Dixit, Terry Richard Wyatt, A. T. Watson, G. T. Zorn, C. Y. Chang, M. F. Turner, Frans Meijers, E. Torrente-Lujan, M. Tecchio, P. Scharff-Hansen, H. G. Evans, X. C. Lou, M. J. Goodrick, R. J. Homer, C. Markus, P. Paschievici, D. Hochman, N. J. Thackray, I. Cohen, Georges Azuelos, H. M. Bosch, S. L. Chu, A. A. Carter, M. Coupland, V. H. Winterer, Wolfram Dietrich Zeuner, P. Taras, Margret Fincke-Keeler, Claudio Grandi, A. Gaidot, M. Kuwano, T. Wlodek, Mitsuaki Nozaki, J. G. Layter, J. F. Kral, R. Van Kooten, K. W. Bell, F. C. Grant, M. J. Oreglia, M. Sproston, M. A. Whalley, R. Lahmann, D. C. Imrie, Max Weber, J. C. Clayton, Erez Etzion, D. E. Plane, A. M. Smith, P. Pfister, J. C. Hill, Stefan Kluth, P. Routenburg, N. Tesch, A. Dieckmann, B. C. Shen, Shlomit Tarem, P. Bentkowski, G. Vasseur, B. Lorazo, C. Wahl, John Hobbs, G. M. Dallavalle, P. Mättig, J. P. Martin, A. Buijs, G. P. Siroli, D. M. Strom, A. K. Honma, W. G. Scott, Christoph Schwick, G. N. Patrick, J. E. Pilcher, G. D. Lafferty, S. Rossberg, C. J. Oram, S. De Jong, J. W. Gary, R. J. Barlow, R. P. Middleton, D. J.P. Dumas, C. Moisan, J. P. Walker, R. Kowalewski, M. Fierro, P. Teixeira-Dias, T. J. Smith, K. Stephens, P. G. Estabrooks, R. K. Keeler, J. von Krogh, J. R. McNutt, M. Sasaki, M. J. Losty, Dave Robinson, P. M. Watkins, G. Quast, John Baines, C. Burgard, B. Schmitt, G. A. Beck, L. A. del Pozo, S. Schreiber, H. O. Ogren, Christoph Geich-Gimbel, T. J. McMahon, J. Schwiening, D. R. Ward, J. Kroll, G. Transtromer, R. K. Carnegie, S. L. Lloyd, F. X. Gentit, J. E. Conboy, J. A. Wilson, A. Pouladdej, R. J. Sobie, W. Schappert, F. S. Merritt, J. A. McKenna, R. F. McGowan, Claude Leroy, J. P. Pansart, J. Mildenberger, Harold Nguyen, N. I. Geddes, Paul Kyberd, F. K. Loebinger, M. W. Redmond, Horst Breuker, A. Rollnik, P. Poffenberger, R. Giacomelli, N. Paz-Jaoshvili, A. Astbury, O. Ganel, A. J. Martin, M. Jimack, C. K. Hargrove, R. G. Kellogg, D. S. Koetke, Stefano Marcellini, James Letts, H. Mes, I. P. Duerdoth, G. Mikenberg, O. Schaile, F. Odorici, J. Banks, N. J. Tresilian, T. Mouthuy, R. D. Heuer, A. Yeaman, Fabrizio Fabbri, N. K. Watson, D. Van den plas, Sachio Komamiya, E. Ros, D. R. Rust, T. P. Kokott, Carla Sbarra, Peter R Hobson, A. M. Rossi, D. Pitman, M. H. Lehto, T. Tsukamoto, T. G. Shears, S. Levegrün, P. Berlich, L. Köpke, B. Boden, B. Poli, H. M. Fischer, A. Michelini, A. C. Janissen, J. R. Carter, and J. Hart
Subjects: Physics, Quantum chromodynamics, Particle physics, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Hadron, Observable, Jet (particle physics), Resonance (particle physics), Nuclear physics, Renormalization, High Energy Physics::Experiment, Engineering (miscellaneous), Energy (signal processing), Particle Physics - Experiment
Abstract: The strong coupling constant, αs, has been determined in hadronic decays of theZ0 resonance, using measurements of seven observables relating to global event shapes, energy correlations and jet rates. The data have been compared with resummed QCD calculations, which are combined with theO(s2) theory. The seven measurements agree to about 10% and the final results, based on a weighted average, is: $$\alpha _s (M_{Z^0 } ) = 0.120 \pm 0.006,$$ where the error includes both experimental and theoretical uncertainties. This value corresponds to renormalization scale$\mu = M_{Z^0 } $ and the error includes the uncertainty in this choice of scale. The present measurement complements previous determinations using theO(s2) QCD matrix elements alone, and yields a compatible result, with comparable errors.
Published: 1993

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