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1. The performance of prototype vacuum phototriodes in the first full sized supercrystal array for the CMS ECAL endcaps

Author: A. B. Lodge, J. Bourotte, MG Probert, Helen F Heath, A.L. Lintern, M. Ukhanov, R. M. Brown, Nikolai Golubev, Y. Goussev, Gavin Davies, Sergei Gninenko, M. Apollonio, Christopher Seez, D.C. Imrie, James John Brooke, I. Semeniouk, D. M. Seliverstov, M. Haguenauer, B. Smith, D. Patalakha, M. Sproston, A. Inyakin, B. Tchuiko, Mikhail Kirsanov, K. W. Bell, Dave Britton, G.J. Barber, E. Devitsin, David Ja Cockerill, E. Mcleod, AD Presland, RD Head, V. Katchanov, R. J. Tapper, V. Postoev, B. Camanzi, Peter R Hobson, Dave M Newbold, S Nash, and G. Ergun
Subjects: Crystal, Physics, Nuclear physics, Nuclear and High Energy Physics, Large Hadron Collider, Electron yield, Electron, Fermion, Photoelectric effect, Instrumentation, Lepton, Magnetic field
Abstract: The performance of prototype vacuum phototriodes is presented from the first full sized supercrystal array for the CMS ECAL endcaps. The array was exposed to high-energy electrons and tested in magnetic fields of up to 3 T, in the CERN North area, in July and August 1999. The mean VPT electron yield, normalised to a naked crystal light yield of 8 photoelectrons/MeV into an HPMT, was found to be 25 electrons/MeV at 3 T for devices from Research Institute Electron, 35 electrons/MeV for devices from Hamamatsu and 18/23 electrons/MeV from Electron Tubes.
Published: 2004

2. Measurement of |Vcb| using decays

Author: G. Abbiendi, K. Ackerstaff, P.F. Akesson, G. Alexander, J. Allison, K.J. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, I. Bailey, A.H. Ball, E. Barberio, R.J. Barlow, J.R. Batley, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, O. Biebel, A. Biguzzi, I.J. Bloodworth, P. Bock, J. Böhme, O. Boeriu, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, R. Davis, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, P. Ferrari, F. Fiedler, M. Fierro, I. Fleck, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, M. Harin-Dirac, A. Hauke, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, T. Kobayashi, M. Kobel, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, F.S. Merritt, H. Mes, I. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, M. Przybycień, A. Quadt, C. Rembser, H. Rick, S.A. Robins, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tarem, R.J. Taylor, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence, S. Towers, T. Trefzger, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Branching fraction, Form factor (quantum field theory), Zero (complex analysis), Value (computer science), 01 natural sciences, Recoil, 0103 physical sciences, Heavy quark effective theory, Matrix element, 010306 general physics
Abstract: The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element Vcb has been measured using B0 to D*l nu decays recorded on the Z0 peak using the OPAL detector at LEP. The D* to D0 pi+ decays were reconstructed both in the particular decay modes D0 to K- pi+ and D0 to K- pi+ pi- and via an inclusive technique. The product of |Vcb| and the decay form factor of the B0 to D* l nu transition at zero recoil F(1) was measured to be F(1)|Vcb| = (37.1+-1.0+-2.0)x10^-3, where the uncertainties are statistical and systematic respectively. By using Heavy Quark Effective Theory calculations for F(1), a value of |Vcb| = (40.7+-1.1+-2.2+-1.6)x 10^-3 was obtained, where the third error is due to theoretical uncertainties in the value of F(1). The branching ratio Br(B0 to D* l nu) was also measured to be (5.26+-0.20+-0.46)%.
Published: 2000

3. Z boson pair production in e+e− collisions at and 189 GeV

Author: G. Abbiendi, K. Ackerstaff, P.F. Akesson, G. Alexander, J. Allison, K.J. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, I. Bailey, A.H. Ball, E. Barberio, R.J. Barlow, J.R. Batley, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, O. Biebel, A. Biguzzi, I.J. Bloodworth, P. Bock, J. Böhme, O. Boeriu, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, R. Davis, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, P. Ferrari, F. Fiedler, M. Fierro, I. Fleck, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, M. Harin-Dirac, A. Hauke, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, T. Kobayashi, M. Kobel, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, F.S. Merritt, H. Mes, I. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, M. Przybycień, A. Quadt, C. Rembser, H. Rick, S.A. Robins, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tarem, R.J. Taylor, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence, S. Towers, T. Trefzger, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, and D. Zer-Zion
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, 010308 nuclear & particles physics, State (functional analysis), 01 natural sciences, Standard Model, Pair production, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010303 astronomy & astrophysics, Lepton
Abstract: A study of Z boson pair production in e+e- annihilation at center-of-mass energies near 183 GeV and 189 GeV is reported. Final states containing only leptons, (l+l-l+l- and l+l-nu nubar), quark and lepton pairs, (q qbar l+l-, q qbar nu nubar) and the all-hadronic final state (q qbar q qbar) are considered. In all states with at least one Z boson decaying hadronically, q qbar and b bbar final states are considered separately using lifetime and event-shape tags, thereby improving the cross-section measurement. At sqrt(s) = 189 GeV the Z-pair cross section was measured to be 0.80 (+0.14-0.13, stat.) (+0.06-0.05, syst.) pb, consistent with the Standard Model prediction. At sqrt(s) = 183 GeV the 95% C.L. upper limit is 0.55 pb. Limits on anomalous ZZgamma and ZZZ couplings are derived.
Published: 2000

4. Search for scalar top and scalar bottom quarks at = 189 GeV at LEP

Author: G Abbiendi, K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, J.R Batley, S Baumann, J Bechtluft, T Behnke, K.W Bell, G Bella, A Bellerive, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, V Blobel, I.J Bloodworth, P Bock, J Böhme, D Bonacorsi, M Boutemeur, S Braibant, P Bright-Thomas, L Brigliadori, R.M Brown, H.J Burckhart, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, C Ciocca, P.E.L Clarke, E Clay, I Cohen, J.E Conboy, O.C Cooke, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, G.M Dallavalle, R Davis, S De Jong, A de Roeck, P Dervan, K Desch, B Dienes, M.S Dixit, J Dubbert, E Duchovni, G Duckeck, I.P Duerdoth, P.G Estabrooks, E Etzion, F Fabbri, A Fanfani, M Fanti, A.A Faust, F Fiedler, M Fierro, I Fleck, R Folman, A Frey, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, J Gascon, S.M Gascon-Shotkin, G Gaycken, C Geich-Gimbel, G Giacomelli, P Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, W Gorn, C Grandi, K Graham, E Gross, J Grunhaus, M Gruwé, G.G Hanson, M Hansroul, M Hapke, K Harder, A Harel, C.K Hargrove, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, M Herndon, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, P.R Hobson, M Hoch, A Hocker, K Hoffman, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, P Igo-Kemenes, D.C Imrie, K Ishii, F.R Jacob, A Jawahery, H Jeremie, M Jimack, C.R Jones, P Jovanovic, T.R Junk, J Kanzaki, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, D.H Kim, A Klier, T Kobayashi, M Kobel, T.P Kokott, M Kolrep, S Komamiya, R.V Kowalewski, T Kress, P Krieger, J von Krogh, T Kuhl, P Kyberd, G.D Lafferty, H Landsman, D Lanske, J Lauber, S.R Lautenschlager, I Lawson, J.G Layter, A.M Lee, D Lellouch, J Letts, L Levinson, R Liebisch, B List, C Littlewood, A.W Lloyd, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Lu, J Ludwig, D Liu, A Macchiolo, A Macpherson, W Mader, M Mannelli, S Marcellini, C Markopoulos, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, S Menke, F.S Merritt, H Mes, J Meyer, A Michelini, S Mihara, G Mikenberg, D.J Miller, R Mir, W Mohr, A Montanari, T Mori, K Nagai, I Nakamura, H.A Neal, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, M.J Oreglia, S Orito, J Pálinkás, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, J Polok, M Przybycień, C Rembser, H Rick, S Robertson, S.A Robins, N Rodning, J.M Roney, S Rosati, K Roscoe, A.M Rossi, Y Rozen, K Runge, O Runolfsson, D.R Rust, K Sachs, T Saeki, O Sahr, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, P Scharff-Hansen, J Schieck, S Schmitt, A Schöning, M Schröder, M Schumacher, C Schwick, W.G Scott, R Seuster, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, S Spagnolo, M Sproston, A Stahl, K Stephens, J Steuerer, K Stoll, D Strom, R Ströhmer, B Surrow, S.D Talbot, P Taras, S Tarem, R Teuscher, M Thiergen, J Thomas, M.A Thomson, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, I Ueda, R Van Kooten, P Vannerem, M Verzocchi, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, J.S White, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, G Yekutieli, V Zacek, and D Zer-Zion
Subjects: Quark, Nuclear and High Energy Physics, Top quark, Particle physics, High Energy Physics::Lattice, Nuclear Theory, FOS: Physical sciences, Fizikai tudományok, 7. Clean energy, 01 natural sciences, Bottom quark, High Energy Physics - Experiment, Charm quark, High Energy Physics - Experiment (hep-ex), Természettudományok, 0103 physical sciences, 010306 general physics, Physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Scalar (physics), Neutralino, High Energy Physics::Experiment, Neutrino, Particle Physics - Experiment, Lepton
Abstract: Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 182 pb-1 at a centre-of-mass energy of 189 GeV collected with the OPAL detector at LEP. No evidence for a signal was found. The 95% confidence level lower limit on the scalar top quark mass is 90.3 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed states of the top quark is zero. In the worst case, when the scalar top quark decouples from the Z boson, the lower limit is 87.2 GeV. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. The complementary decay mode of the scalar top quark decaying into a bottom quark, a charged lepton and a scalar neutrino has also been studied. From a search for the scalar bottom quark, a mass limit of 88.6 GeV was obtained if the mass difference between the scalar bottom quark and the lightest neutralino is larger than 7 GeV. These limits significantly improve the previous OPAL limits., 18 pages, LaTeX, including 4 eps figures, submitted to Physics Letters B
Published: 1999

5. Colour reconnection studies in e+e−→W+W− at GeV

Author: G. Abbiendi, K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, M. Hoch, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Hadron, Observable, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Charged particle, 0103 physical sciences, Statistical precision, High Energy Physics::Experiment, Rapidity, Multiplicity (chemistry), 010306 general physics, Boson
Abstract: The predicted effects of final state interactions such as colour reconnection are investigated by measuring properties of hadronic decays of W bosons, recorded at a centre-of-mass energy of sqrt(s)=182.7 GeV in the OPAL detector at LEP. Dependence on the modelling of hadronic W decays is avoided by comparing W+W- -> qqqq events with the non-leptonic component of W+W- -> qqlnu events. The scaled momentum distribution, its mean value, x_p, and that of the charged particle multiplicity, n_ch, are measured and found to be consistent in the two channels. The measured differences are: Diff(x_p) = +0.7 +- 0.8 +- 0.6 and Diff(n_ch) = (-0.09 +- 0.09 +-0.05)*10**-2. In addition, measurements of rapidity and thrust are performed for W+W- -> qqqq events. The data are described well by standard QCD models and disfavour one model of colour reconnection within the ARIADNE program. The current implementation of the ELLIS-GEIGER model of colour reconnection is excluded. At the current level of statistical precision no evidence for colour reconnection effects was found in the observables studied. The predicted effect of colour reconnection on OPAL measurements of M_W is also quantified in the context of models studied.
Published: 1999

6. Search for baryon and lepton number violating Z0 decays

Author: G. Abbiendi, K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, M. Hoch, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Detector, FOS: Physical sciences, Fizikai tudományok, Charge (physics), 01 natural sciences, Lepton number, High Energy Physics - Experiment, Baryon, High Energy Physics - Experiment (hep-ex), Természettudományok, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, Conjugate
Abstract: Using data collected with the OPAL detector at LEP, we have searched for the processes e+e- -> Z0 -> p e-, p mu- and the charge conjugate final-states. These would violate the conservation of the baryon-number B, lepton-number L and the fermion-number n = (B+L). No evidence for such decays has been found, and the 95% confidence level upper limits on the partial widths Z0 -> p e and Z0 -> p mu are found to be 4.6 and 4.4 keV respectively., 16 pages, LaTeX, 2 ps figs included, submitted to Physics Letters B
Published: 1999

7. Multi-photon production in e+e− collisions at =183 GeV

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, J. Böhme, M. Boutemeur, S. Braibant, P. Bright-Thomas, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, M. Doucet, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, T. Schorner, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, R. Tafirout, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, R. Van Kooten, P. Vannerem, M. Verzocchi, P. Vikas, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Luminosity (scattering theory), Photon, 010308 nuclear & particles physics, Branching fraction, Astrophysics::High Energy Astrophysical Phenomena, Resonance, Lambda, 01 natural sciences, 7. Clean energy, Excited state, 0103 physical sciences, High Energy Physics::Experiment, Invariant mass, 010306 general physics, Energy (signal processing)
Abstract: The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a centre-of-mass energy of 183 GeV. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Lambda+ > 233 GeV and Lambda- > 265 GeV as well as a mass limit for an excited electron, M(e*) > 227 GeV assuming equal e*egamma and eegamma couplings. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons.
Published: 1998

8. An upper limit on the anomalous magnetic moment of the τ lepton

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, M. Evans, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, D.G. Fong, M. Foucher, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, D.E. Hutchcroft, P. Igo-Kemenes, D.C. Imrie, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, J. Kanzaki, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, B. List, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Lui, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markopoulos, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, N.J. Oldershaw, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, C. Rembser, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, A.M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, R.P.B. Sieberg, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, R. Ströhmer, P. Szymanski, R. Tafirout, S.D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, P. Utzat, R. Van Kooten, P. Vannerem, M. Verzocchi, P. Vikas, E.H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Anomalous magnetic dipole moment, 010308 nuclear & particles physics, Form factor (quantum field theory), 01 natural sciences, High Energy Physics - Experiment, Dipole, 0103 physical sciences, Magnetic form factor, Radiative transfer, Vertex (curve), High Energy Physics::Experiment, Production (computer science), 010306 general physics, Particle Physics - Experiment, Lepton
Abstract: Using radiative Z^0 -> \tau^+ \tau^- \gamma events collected with the OPAL detector at LEP at \sqrt{s}= M_Z during 1990-95, a direct study of the electromagnetic current at the \tau\gamma vertex has been performed in terms of the anomalous magnetic form factor F_2 of the \tau lepton. The analysis is based on a data sample of 1429 e^+ e^- -> \tau^+ \tau^- \gamma events which are examined for a deviation from the expectation with F_2 = 0. From the non-observation of anomalous \tau^+ \tau^- \gamma production a limit of -0.068 < F_2 < 0.065 is obtained. This can also be interpreted as a limit on the electric dipole form factor F_3 as -3.8 x 10^-16 e-cm < eF_3 < 3.6 x 10^-16 e-cm. The above ranges are valid at the 95% confidence level., Comment: 20 pages, LaTeX, uses a4p.sty, 4 eps figures included, submitted to Phys. Lett. B
Published: 1998

9. Search for an excess in the production of four-jet events from e+e− collisions at =130–184 GeV

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, M. Evans, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, D.G. Fong, M. Foucher, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, D.E. Hutchcroft, P. Igo-Kemenes, D.C. Imrie, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, J. Kanzaki, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, B. List, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Lui, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markopoulos, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, N.J. Oldershaw, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, C. Rembser, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, A.M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, R. Ströhmer, P. Szymanski, R. Tafirout, S.D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, P. Utzat, R. Van Kooten, P. Vannerem, M. Verzocchi, P. Vikas, E.H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Aleph, 010308 nuclear & particles physics, FOS: Physical sciences, Jet (particle physics), 01 natural sciences, High Energy Physics - Experiment, Standard Model, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, High Energy Physics::Experiment, Production (computer science), 010306 general physics, Particle Physics - Experiment
Abstract: Events with four distinct jets from e^+e^- collisions, collected by the OPAL detector at centre-of-mass energies between 130 and 184 GeV, are analysed for a peak in the sum of dijet masses. This search is motivated by the ALEPH Collaboration's observation of a clear excess of events with dijet mass sums close to 105 GeV in data taken at centre-of-mass energies of 130 and 136 GeV in 1995. We have observed no significant excess of four-jet events compared to the Standard Model expectation for any dijet mass sum at any energy. Our observation is inconsistent with the excess observed by ALEPH in 1995. Upper limits are determined on the production cross-section as a function of the dijet mass sum., Comment: 24 pages, LaTeX, uses a4p.sty, 5 eps figures included, submitted to Physics Letters B
Published: 1998

10. Measurements of the Bs0 and Λb0 lifetimes

Author: K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, R Bartoldus, J.R Batley, S Baumann, J Bechtluft, C Beeston, T Behnke, A.N Bell, K.W Bell, G Bella, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, S.D Bird, V Blobel, I.J Bloodworth, J.E Bloomer, M Bobinski, P Bock, D Bonacorsi, M Boutemeur, S Braibant, L Brigliadori, R.M Brown, H.J Burckhart, C Burgard, R Bürgin, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, P.E.L Clarke, I Cohen, J.E Conboy, O.C Cooke, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, C Dallapiccola, G.M Dallavalle, R Davis, S De Jong, L.A del Pozo, K Desch, B Dienes, M.S Dixit, M Doucet, E Duchovni, G Duckeck, I.P Duerdoth, D Eatough, J.E.G Edwards, P.G Estabrooks, H.G Evans, M Evans, F Fabbri, A Fanfani, M Fanti, A.A Faust, L Feld, F Fiedler, M Fierro, H.M Fischer, I Fleck, R Folman, D.G Fong, M Foucher, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, J Gascon, S.M Gascon-Shotkin, N.I Geddes, C Geich-Gimbel, T Geralis, G Giacomelli, P Giacomelli, R Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, M.J Goodrick, W Gorn, C Grandi, E Gross, J Grunhaus, M Gruwé, C Hajdu, G.G Hanson, M Hansroul, M Hapke, C.K Hargrove, P.A Hart, C Hartmann, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, M Herndon, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, S.J Hillier, P.R Hobson, A Hocker, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, D.E Hutchcroft, P Igo-Kemenes, D.C Imrie, M.R Ingram, K Ishii, A Jawahery, P.W Jeffreys, H Jeremie, M Jimack, A Joly, C.R Jones, G Jones, M Jones, U Jost, P Jovanovic, T.R Junk, J Kanzaki, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, J Kirk, A Klier, S Kluth, T Kobayashi, M Kobel, D.S Koetke, T.P Kokott, M Kolrep, S Komamiya, T Kress, P Krieger, J von Krogh, P Kyberd, G.D Lafferty, R Lahmann, W.P Lai, D Lanske, J Lauber, S.R Lautenschlager, J.G Layter, D Lazic, A.M Lee, E Lefebvre, D Lellouch, J Letts, L Levinson, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Ludwig, D Lui, A Macchiolo, A Macpherson, M Mannelli, S Marcellini, C Markopoulos, C Markus, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, S Menke, F.S Merritt, H Mes, J Meyer, A Michelini, G Mikenberg, D.J Miller, A Mincer, R Mir, W Mohr, A Montanari, T Mori, U Müller, S Mihara, K Nagai, I Nakamura, H.A Neal, B Nellen, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, A Oh, N.J Oldershaw, M.J Oreglia, S Orito, J Pálinkás, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, A Posthaus, C Rembser, S Robertson, S.A Robins, N Rodning, J.M Roney, A Rooke, A.M Rossi, P Routenburg, Y Rozen, K Runge, O Runolfsson, U Ruppel, D.R Rust, R Rylko, K Sachs, T Saeki, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, F Scharf, P Scharff-Hansen, J Schieck, P Schleper, B Schmitt, S Schmitt, A Schöning, M Schröder, H.C Schultz-Coulon, M Schumacher, C Schwick, W.G Scott, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skillman, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, R.W Springer, M Sproston, K Stephens, J Steuerer, B Stockhausen, K Stoll, D Strom, R Ströhmer, P Szymanski, R Tafirout, S.D Talbot, S Tanaka, P Taras, S Tarem, R Teuscher, M Thiergen, M.A Thomson, E von Törne, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, P Utzat, R Van Kooten, M Verzocchi, P Vikas, E.H Vokurka, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, J.S White, B Wilkens, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, G Yekutieli, V Zacek, and D Zer-Zion
Subjects: Baryon, Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, 0103 physical sciences, Hadron, High Energy Physics::Experiment, 010306 general physics, Lambda, 01 natural sciences, Bar (unit)
Abstract: This paper presents updated measurements of the lifetimes of the B^0_s meson and the \Lambda_b baryon using 4.4 million hadronic Z^0 decays recorded by the OPAL detector at LEP from 1990 to 1995. A sample of B^0_s decays is obtained using D_s^- \ell^+ combinations, where the D_s^- is fully reconstructed in the \phi \pi^-, K^*0 K^- and K^- K^0_S decay channels and partially reconstructed in the \phi \ell^- \nu(bar) X decay mode. A sample of \Lambda_b decays is obtained using \Lambda_c^+ \ell^- combinations, where the \Lambda_c^+ is fully reconstructed in its decay to a p K^- \pi^+ final state and partially reconstructed in the \Lambda \ell^+ \nu X decay channel. From 172 +/- 28 D_s^- \ell^+ combinations attributed to B^0_s decays, the measured lifetime is \tau(B^0_s) = 1.50 +0.16 -0.15 +/- 0.04 ps, where the errors are statistical and systematic, respectively. From the 129 +\- 25 \Lamda_c^+ \ell^- combinations attributed to \Lambda_b decays, the measured lifetime \tau(\Lambda_b) = 1.29 +0.24 -0.22 +/- 0.06 ps, where the errors are statistical and systematic, respectively.
Published: 1998

11. Search for the Bc meson in hadronic Z0 decays

Author: K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, R Bartoldus, J.R Batley, S Baumann, J Bechtluft, C Beeston, T Behnke, A.N Bell, K.W Bell, G Bella, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, S.D Bird, V Blobel, I.J Bloodworth, J.E Bloomer, M Bobinski, P Bock, D Bonacorsi, M Boutemeur, S Braibant, L Brigliadori, R.M Brown, H.J Burckhart, C Burgard, R Bürgin, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, P.E.L Clarke, I Cohen, J.E Conboy, O.C Cooke, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, C Dallapiccola, G.M Dallavalle, R Davis, S De Jong, L.A del Pozo, K Desch, B Dienes, M.S Dixit, M Doucet, E Duchovni, G Duckeck, I.P Duerdoth, D Eatough, J.E.G Edwards, P.G Estabrooks, H.G Evans, M Evans, F Fabbri, A Fanfani, M Fanti, A.A Faust, L Feld, F Fiedler, M Fierro, H.M Fischer, I Fleck, R Folman, D.G Fong, M Foucher, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, J Gascon, S.M Gascon-Shotkin, N.I Geddes, C Geich-Gimbel, T Geralis, G Giacomelli, P Giacomelli, R Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, M.J Goodrick, W Gorn, C Grandi, E Gross, J Grunhaus, M Gruwé, C Hajdu, G.G Hanson, M Hansroul, M Hapke, C.K Hargrove, P.A Hart, C Hartmann, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, M Herndon, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, S.J Hillier, P.R Hobson, A Hocker, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, D.E Hutchcroft, P Igo-Kemenes, D.C Imrie, M.R Ingram, K Ishii, A Jawahery, P.W Jeffreys, H Jeremie, M Jimack, A Joly, C.R Jones, G Jones, M Jones, U Jost, P Jovanovic, T.R Junk, J Kanzaki, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, J Kirk, A Klier, S Kluth, T Kobayashi, M Kobel, D.S Koetke, T.P Kokott, M Kolrep, S Komamiya, T Kress, P Krieger, J von Krogh, P Kyberd, G.D Lafferty, R Lahmann, W.P Lai, D Lanske, J Lauber, S.R Lautenschlager, J.G Layter, D Lazic, A.M Lee, E Lefebvre, D Lellouch, J Letts, L Levinson, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Ludwig, D Lui, A Macchiolo, A Macpherson, M Mannelli, S Marcellini, C Markopoulos, C Markus, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, S Menke, F.S Merritt, H Mes, J Meyer, A Michelini, G Mikenberg, D.J Miller, A Mincer, R Mir, W Mohr, A Montanari, T Mori, U Müller, S Mihara, K Nagai, I Nakamura, H.A Neal, B Nellen, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, A Oh, N.J Oldershaw, M.J Oreglia, S Orito, J Pálinkás, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, A Posthaus, C Rembser, S Robertson, S.A Robins, N Rodning, J.M Roney, A Rooke, A.M Rossi, P Routenburg, Y Rozen, K Runge, O Runolfsson, U Ruppel, D.R Rust, R Rylko, K Sachs, T Saeki, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, F Scharf, P Scharff-Hansen, J Schieck, P Schleper, B Schmitt, S Schmitt, A Schöning, M Schröder, H.C Schultz-Coulon, M Schumacher, C Schwick, W.G Scott, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skillman, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, R.W Springer, M Sproston, K Stephens, J Steuerer, B Stockhausen, K Stoll, D Strom, R Ströhmer, P Szymanski, R Tafirout, S.D Talbot, S Tanaka, P Taras, S Tarem, R Teuscher, M Thiergen, M.A Thomson, E von Törne, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, P Utzat, R Van Kooten, M Verzocchi, P Vikas, E.H Vokurka, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, J.S White, B Wilkens, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, G Yekutieli, V Zacek, and D Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Meson, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Hadron, FOS: Physical sciences, Electron, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment
Abstract: A search for decays of the B_c meson was performed using data collected from 1990-1995 with the OPAL detector on or near the Z peak at LEP. The decay channels B_c^+ -> J/psi pi^+, B_c^+ -> J/psi a_1^+ and B_c^+ -> J/psi ell^+ nu were investigated, where ell denotes an electron or a muon. Two candidates are observed in the mode B_c^+ -> J/psi pi^+, with an estimated background of (0.63 +/- 0.20) events. The weighted mean of the masses of the two candidates is (6.32 +/- 0.06) GeV/c^2, which is consistent with the predicted mass of the B_c meson. One candidate event is observed in the mode B_c^+ -> J/psi ell^+ nu with an estimated background of (0.82 +/- 0.19) events. No candidate events are observed in the B_c^+ -> J/psi a_1^+ decay mode, with an estimated background of (1.10 +/- 0.22) events. Upper bounds at the 90% confidence level are set on the production rates for these processes., 18 pages, LaTeX, uses a4p.sty, 6 eps figures included, submitted to Phys. Lett. B
Published: 1998

12. Development of large-area, air-stable photocathodes for the ultraviolet

Author: D.C. Imrie, A.H. Moghul, Kevin Wells, Vladimir Peskov, and Georges Charpak
Subjects: Physics, Nuclear and High Energy Physics, Borosilicate glass, business.industry, chemistry.chemical_element, Substrate (electronics), medicine.disease_cause, Copper, Photocathode, Optics, chemistry, Aluminium, medicine, Optoelectronics, Quantum efficiency, Thin film, business, Instrumentation, Ultraviolet
Abstract: Results are presented for the reflection quantum efficiency as a function of wavelength of thin films of four organometallic materials, triferrocenyl phosphine, dimethyl aminoferrocene, porphyrin iron complex and 1′1-trimethylene ferrocenephane. The quantum efficiency of thin films of CsI vacuum evaporated on to treshly-preared copper or aluminium surfaces on a borosilicate glass substrate have also been measured. The reflective quantum efficiency increases substantially if the photocathode is subjected to prolonged flushing in dry CH4 or argon gas.
Published: 1991

13. Search for Higgs Bosons and Other Massive States decaying into two Photons in $e^{+}e^{-}$ Collisions at 189 GeV

Author: G Abbiendi, K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, J.R Batley, S Baumann, J Bechtluft, T Behnke, K.W Bell, G Bella, A Bellerive, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, I.J Bloodworth, P Bock, J Böhme, D Bonacorsi, M Boutemeur, S Braibant, P Bright-Thomas, L Brigliadori, R.M Brown, H.J Burckhart, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, C Ciocca, P.E.L Clarke, E Clay, I Cohen, J.E Conboy, O.C Cooke, J Couchman, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, G.M Dallavalle, R Davis, S De Jong, A de Roeck, P Dervan, K Desch, B Dienes, M.S Dixit, J Dubbert, E Duchovni, G Duckeck, I.P Duerdoth, P.G Estabrooks, E Etzion, F Fabbri, A Fanfani, M Fanti, A.A Faust, L Feld, F Fiedler, M Fierro, I Fleck, A Frey, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, G Gaycken, C Geich-Gimbel, G Giacomelli, P Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, W Gorn, C Grandi, K Graham, E Gross, J Grunhaus, M Gruwé, C Hajdu, G.G Hanson, M Hansroul, M Hapke, K Harder, A Harel, C.K Hargrove, M Harin-Dirac, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, P.R Hobson, A Hocker, K Hoffman, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, P Igo-Kemenes, D.C Imrie, K Ishii, F.R Jacob, A Jawahery, H Jeremie, M Jimack, C.R Jones, P Jovanovic, T.R Junk, N Kanaya, J Kanzaki, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, D.H Kim, A Klier, T Kobayashi, M Kobel, T.P Kokott, M Kolrep, S Komamiya, R.V Kowalewski, T Kress, P Krieger, J von Krogh, T Kuhl, P Kyberd, G.D Lafferty, H Landsman, D Lanske, J Lauber, I Lawson, J.G Layter, D Lellouch, J Letts, L Levinson, R Liebisch, B List, C Littlewood, A.W Lloyd, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Lu, J Ludwig, D Liu, A Macchiolo, A Macpherson, W Mader, M Mannelli, S Marcellini, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, P Mendez-Lorenzo, F.S Merritt, H Mes, A Michelini, S Mihara, G Mikenberg, D.J Miller, W Mohr, A Montanari, T Mori, K Nagai, I Nakamura, H.A Neal, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, A Okpara, M.J Oreglia, S Orito, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, J Polok, M Przybycień, A Quadt, C Rembser, H Rick, S Robertson, S.A Robins, N Rodning, J.M Roney, S Rosati, K Roscoe, A.M Rossi, Y Rozen, K Runge, O Runolfsson, D.R Rust, K Sachs, T Saeki, O Sahr, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, P Scharff-Hansen, J Schieck, S Schmitt, A Schöning, M Schröder, M Schumacher, C Schwick, W.G Scott, R Seuster, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, S Spagnolo, M Sproston, A Stahl, K Stephens, J Steuerer, K Stoll, D Strom, R Ströhmer, B Surrow, S.D Talbot, P Taras, S Tarem, R Teuscher, M Thiergen, J Thomas, M.A Thomson, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, I Ueda, R Van Kooten, P Vannerem, M Verzocchi, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, D Wetterling, J.S White, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, V Zacek, and D Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, FOS: Physical sciences, Fizikai tudományok, Fermion, Scalar boson, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Természettudományok, 0103 physical sciences, Higgs boson, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, Boson
Abstract: A search is described for the generic process e+e- to X Y, where X is a neutral heavy scalar boson decaying into a pair of photons, and Y is a neutral heavy boson (scalar or vector) decaying into a fermion pair. The search is motivated mainly by the cases where either X, or both X and Y, are Higgs bosons. In particular, we investigate the case where X is the Standard Model Higgs boson and Y the Z0 boson. Other models with enhanced Higgs boson decay couplings to photon pairs are also considered. The present search combines the data set collected by the OPAL collaboration at 189 GeV collider energy, having an integrated luminosity of 182.6pb-1, with data samples collected at lower energies. The search results have been used to put 95% confidence level bounds, as functions of the mass of X, on the product of the cross-section and the relevant branching ratios, both in a model independent manner and for the particular models considered., Comment: 21 pages, LaTeX, including 5 eps figures, accepted by Phys. Lett. B
Published: 1999

14. Measurement of the W Mass and Width in $e^{+}e^{-}$ Collisions at 183 GeV

Author: G. Abbiendi, K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, M. Hoch, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, FOS: Physical sciences, 01 natural sciences, Direct measure, Standard Model, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, Particle Physics - Experiment
Abstract: Using a data sample of 57 pb-1 recorded at a centre-of-mass energy of 183 GeV with the Opal detector at LEP, 282 W+W- -> qqqq and 300 W+W- -> qqlnu candidate events are used to obtain a measurement of the mass of the W boson, W_W = 80.39 +- 0.13(stat.) +- 0.05(syst.) GeV assuming the Standard Model relation between M_W and Gam_W. A second fit provides a direct measure of the width of the W boson and gives Gam_W = 1.96 +- 0.34(stat.) +- 0.20(syst.) GeV. These results are combined with previous OPAL results to obtain M_W = 80.38 +- 0.12(stat.) +- 0.05(syst.) GeV and Gam_W = 1.84 +- 0.32(stat.) +- 0.20(syst.) GeV., 21 pages, LaTeX, 4 eps figs included, submitted to Physics Letters B
Published: 1998

15. Search for Higgs Bosons and New Particles Decaying into Two Photons at sqrt(s) = 183 GeV

Author: K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, R Bartoldus, J.R Batley, S Baumann, J Bechtluft, T Behnke, K.W Bell, G Bella, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, S.D Bird, V Blobel, I.J Bloodworth, M Bobinski, P Bock, J Böhme, M Boutemeur, S Braibant, P Bright-Thomas, R.M Brown, H.J Burckhart, C Burgard, R Bürgin, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, C Ciocca, P.E.L Clarke, E Clay, I Cohen, J.E Conboy, O.C Cooke, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, G.M Dallavalle, R Davis, S De Jong, L.A del Pozo, A de Roeck, K Desch, B Dienes, M.S Dixit, M Doucet, J Dubbert, E Duchovni, G Duckeck, I.P Duerdoth, D Eatough, P.G Estabrooks, E Etzion, H.G Evans, F Fabbri, A Fanfani, M Fanti, A.A Faust, F Fiedler, M Fierro, H.M Fischer, I Fleck, R Folman, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, J Gascon, S.M Gascon-Shotkin, C Geich-Gimbel, T Geralis, G Giacomelli, P Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, W Gorn, C Grandi, E Gross, J Grunhaus, M Gruwé, G.G Hanson, M Hansroul, M Hapke, C.K Hargrove, C Hartmann, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, M Herndon, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, S.J Hillier, P.R Hobson, A Hocker, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, P Igo-Kemenes, D.C Imrie, K Ishii, F.R Jacob, A Jawahery, H Jeremie, M Jimack, A Joly, C.R Jones, P Jovanovic, T.R Junk, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, A Klier, S Kluth, T Kobayashi, M Kobel, D.S Koetke, T.P Kokott, M Kolrep, S Komamiya, R.V Kowalewski, T Kress, P Krieger, J von Krogh, P Kyberd, G.D Lafferty, D Lanske, J Lauber, S.R Lautenschlager, I Lawson, J.G Layter, D Lazic, A.M Lee, E Lefebvre, D Lellouch, J Letts, L Levinson, R Liebisch, B List, C Littlewood, A.W Lloyd, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Ludwig, D Liu, A Macchiolo, A Macpherson, M Mannelli, S Marcellini, C Markopoulos, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, S Menke, F.S Merritt, H Mes, J Meyer, A Michelini, S Mihara, G Mikenberg, D.J Miller, R Mir, W Mohr, A Montanari, T Mori, K Nagai, I Nakamura, H.A Neal, B Nellen, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, M.J Oreglia, S Orito, J Pálinkás, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, J Polok, M Przybycień, C Rembser, H Rick, S Robertson, S.A Robins, N Rodning, J.M Roney, K Roscoe, A.M Rossi, Y Rozen, K Runge, O Runolfsson, D.R Rust, K Sachs, T Saeki, O Sahr, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, F Scharf, P Scharff-Hansen, J Schieck, B Schmitt, S Schmitt, A Schöning, T Schorner, M Schröder, M Schumacher, C Schwick, W.G Scott, R Seuster, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, M Sproston, A Stahl, K Stephens, J Steuerer, K Stoll, D Strom, R Ströhmer, R Tafirout, S.D Talbot, S Tanaka, P Taras, S Tarem, R Teuscher, M Thiergen, M.A Thomson, E von Törne, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, R Van Kooten, P Vannerem, M Verzocchi, P Vikas, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, J.S White, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, G Yekutieli, V Zacek, and D Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Gauge boson, Particle physics, Photon, 010308 nuclear & particles physics, Hadron, Scalar (mathematics), High Energy Physics::Phenomenology, FOS: Physical sciences, Fermion, 01 natural sciences, 3. Good health, Standard Model, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Higgs boson, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, Boson
Abstract: A search for the resonant production of high mass photon pairs associated with a leptonic or hadronic system has been performed using a data sample of 57.7 pb-1 collected at an average center-of-mass energy of 182.6 GeV with the OPAL detector at LEP. No evidence for contributions from non-Standard Model physics processes was observed. The observed candidates are used to place limits on BR (H to gamma gamma) assuming a Standard Model production rate for Higgs boson masses up to 92 GeV, and on the production cross section for a scalar resonance decaying into di-photons up to a mass of 170 GeV. Upper limits on the product of cross section and branching ratios, sigma(e+e- to XY) * BR(X to gamma gamma) * BR(Y to f fbar) as low as 70fb are obtained over the M(X) range 10 - 170 GeV for the case where 10 < M(Y) < 160 GeV and M(X)+M(Y) > 90 GeV, independent of the nature of Y provided it decays to a fermion pair and has negligible width. Higgs scalars which couple only to gauge bosons at Standard Model strength are ruled out up to a mass of 90.0 GeV at the 95% confidence level. Limits are also placed on non-minimal Higgs sectors having triplet representations., 21 pages, LaTeX, 4 eps figures included, submitted to Physics Letters B
Published: 1998

16. Measurement of the average polarization of b baryons in hadronic $Z^0$ decays

Author: G. Abbiendi, K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Semileptonic decay, Nuclear and High Energy Physics, Particle physics, Missing energy, 010308 nuclear & particles physics, Hadron, Nuclear Theory, High Energy Physics::Phenomenology, FOS: Physical sciences, Lambda baryon, 01 natural sciences, High Energy Physics - Experiment, Baryon, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, High Energy Physics::Experiment, Baryon number, Neutrino, 010306 general physics, Particle Physics - Experiment, Lepton
Abstract: In the Standard Model, b quarks produced in e^+e^- annihilation at the Z^0 peak have a large average longitudinal polarization of -0.94. Some fraction of this polarization is expected to be transferred to b-flavored baryons during hadronization. The average longitudinal polarization of weakly decaying b baryons, , is measured in approximately 4.3 million hadronic Z^0 decays collected with the OPAL detector between 1990 and 1995 at LEP. Those b baryons that decay semileptonically and produce a \Lambda baryon are identified through the correlation of the baryon number of the \Lambda and the electric charge of the lepton. In this semileptonic decay, the ratio of the neutrino energy to the lepton energy is a sensitive polarization observable. The neutrino energy is estimated using missing energy measurements. From a fit to the distribution of this ratio, the value = -0.56^{+0.20}_{-0.13} +/- 0.09 is obtained, where the first error is statistical and the second systematic., Comment: 19 pages, LaTeX, 4 eps figures included, submitted to Phys. Lett. B
Published: 1998

17. Measurement of the Q(2) evolution of the photon structure function F-2(gamma)

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, T. Barillari, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, C. Beeston, T. Behnke, A.N. Bell, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, J.E. Bloomer, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, B.T. Bouwens, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, R. Davies, S. De Jong, L.A. del Pozo, K. Desch, B. Dienes, M.S. Dixit, E. do Couto e Silva, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, J.E.G. Edwards, P.G. Estabrooks, H.G. Evans, M. Evans, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, D.G. Fong, M. Foucher, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, D.E. Hutchcroft, P. Igo-Kemenes, D.C. Imrie, M.R. Ingram, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, G. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, G. Mikenberg, D.J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, M. Morii, U. Müller, S. Mihara, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, N.J. Oldershaw, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, M.J. Pearce, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, D.L. Rees, D. Rigby, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, E. Ros, A.M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R. Rust, R. Rylko, K. Sachs, T. Saeki, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, P. Schenk, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, H.C. Schultz-Coulon, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, P. Szymanski, R. Tafirout, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, P. Utzat, R. Van Kooten, M. Verzocchi, P. Vikas, E.H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, B. Wilkens, G.W. Wilson, J.A. Wilson, G. Wolf, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Range (particle radiation), 010308 nuclear & particles physics, 2-Photon Production Processes, Microvertex Detector, FOS: Physical sciences, LEP, Generator, 01 natural sciences, Photon structure function, Luminosity, High Energy Physics - Experiment, Q2, Scattering, GEV2, High Energy Physics - Experiment (hep-ex), High-Energy, 0103 physical sciences, Leading Order, 010306 general physics, Opal Detector, Particle Physics - Experiment
Abstract: New measurements are presented of the photon structure function F_2^gamma(Q) at four values of Q^2 between 9 and 59 GeV/c^2 based on data collected with the OPAL detector at centre-of-mass energies of 161-172 GeV, with a total integrated luminosity of 18.1 pb^-1. The evolution of F_2^gamma with Q^2 in bins of x is determined in the Q^2 range from 1.86 to 135 GeV/c^2 using data taken at centre-of-mass energies of 91 GeV and 161-172 GeV. F_2^gamma is observed to increase with Q^2 with a slope of 1/alpha_em dF_2^gamma/dln(Q^2) = 0.10 +0.05 -0.03 measured in the range 0.1 < x < 0.6., 22 pages, LaTeX, 4 eps figures included, accepted by Phys. Lett. B
Published: 1998

18. Production of Chi_c2 Mesons in Photon-Photon Collisions at LEP

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, T. Barillari, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, J. Böhme, M. Boutemeur, S. Braibant, P. Bright-Thomas, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Meson, 010308 nuclear & particles physics, Branching fraction, Detector, FOS: Physical sciences, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Production (computer science), High Energy Physics::Experiment, Channel (broadcasting), 010306 general physics, Particle Physics - Experiment
Abstract: We present an observation at LEP of the production of chi_c2 mesons in the collisions of two quasi-real photons using the OPAL detector. The chi_c2 mesons are reconstructed in the decay channel Chi_c2 to J/psi gamma to l+l- gamma (with l= e,mu) using all data taken at e+e- centre-of-mass energies of 91 and 183 GeV, corresponding to integrated luminosities of 167 and 55 pb-1 respectively. The two-photon width of the Chi_2 is determined to be 1.76 +- 0.47 +- 0.37 +- 0.15 keV where the first error is statistical, the second is systematic and the third comes from branching ratio uncertainties., Comment: 18 pages, LaTeX, 6 eps figures included, submitted to Physics Letters B
Published: 1998
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19. Search for stable and long-lived massive charged particles in e(+)e(-) collisions at root s=130-183 GeV

Author: K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, R Bartoldus, J.R Batley, S Baumann, J Bechtluft, T Behnke, K.W Bell, G Bella, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, S.D Bird, V Blobel, I.J Bloodworth, M Bobinski, P Bock, D Bonacorsi, M Boutemeur, S Braibant, L Brigliadori, R.M Brown, H.J Burckhart, C Burgard, R Bürgin, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, P.E.L Clarke, I Cohen, J.E Conboy, O.C Cooke, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, C Dallapiccola, G.M Dallavalle, R Davis, S De Jong, L.A del Pozo, A de Roeck, K Desch, B Dienes, M.S Dixit, M Doucet, E Duchovni, G Duckeck, I.P Duerdoth, D Eatough, P.G Estabrooks, E Etzion, H.G Evans, M Evans, F Fabbri, A Fanfani, M Fanti, A.A Faust, L Feld, F Fiedler, M Fierro, H.M Fischer, I Fleck, R Folman, D.G Fong, M Foucher, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, J Gascon, S.M Gascon-Shotkin, N.I Geddes, C Geich-Gimbel, T Geralis, G Giacomelli, P Giacomelli, R Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, M.J Goodrick, W Gorn, C Grandi, E Gross, J Grunhaus, M Gruwé, C Hajdu, G.G Hanson, M Hansroul, M Hapke, C.K Hargrove, P.A Hart, C Hartmann, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, M Herndon, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, S.J Hillier, P.R Hobson, A Hocker, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, D.E Hutchcroft, P Igo-Kemenes, D.C Imrie, K Ishii, A Jawahery, P.W Jeffreys, H Jeremie, M Jimack, A Joly, C.R Jones, M Jones, U Jost, P Jovanovic, T.R Junk, J Kanzaki, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, J Kirk, A Klier, S Kluth, T Kobayashi, M Kobel, D.S Koetke, T.P Kokott, M Kolrep, S Komamiya, R.V Kowalewski, T Kress, P Krieger, J von Krogh, P Kyberd, G.D Lafferty, R Lahmann, W.P Lai, D Lanske, J Lauber, S.R Lautenschlager, I Lawson, J.G Layter, D Lazic, A.M Lee, E Lefebvre, D Lellouch, J Letts, L Levinson, B List, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Ludwig, D Lui, A Macchiolo, A Macpherson, M Mannelli, S Marcellini, C Markopoulos, C Markus, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, S Menke, F.S Merritt, H Mes, J Meyer, A Michelini, S Mihara, G Mikenberg, D.J Miller, A Mincer, R Mir, W Mohr, A Montanari, T Mori, K Nagai, I Nakamura, H.A Neal, B Nellen, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, A Oh, N.J Oldershaw, M.J Oreglia, S Orito, J Pálinkás, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, A Posthaus, C Rembser, S Robertson, S.A Robins, N Rodning, J.M Roney, A Rooke, A.M Rossi, P Routenburg, Y Rozen, K Runge, O Runolfsson, U Ruppel, D.R Rust, K Sachs, T Saeki, O Sahr, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, F Scharf, P Scharff-Hansen, J Schieck, P Schleper, B Schmitt, S Schmitt, A Schöning, M Schröder, M Schumacher, C Schwick, W.G Scott, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skillman, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, R.W Springer, M Sproston, K Stephens, J Steuerer, B Stockhausen, K Stoll, D Strom, R Ströhmer, P Szymanski, R Tafirout, S.D Talbot, P Taras, S Tarem, R Teuscher, M Thiergen, M.A Thomson, E von Törne, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, I Ueda, P Utzat, R Van Kooten, P Vannerem, M Verzocchi, P Vikas, E.H Vokurka, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, J.S White, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, G Yekutieli, V Zacek, and D Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Range (particle radiation), Muon, 010308 nuclear & particles physics, Detector, Scalar (mathematics), Charge (physics), 01 natural sciences, Electric charge, Charged particle, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, Lepton
Abstract: A search for stable and long-lived massive particles of electric charge |Q/e| = 1 or 2/3, pair-produced in e+e- collisions at centre-of-mass energies from 130 to 183 GeV, is reported by the OPAL collaboration at LEP. No evidence for production of these particles was observed in a mass range between 45 and 89.5 GeV. Model-independent upper limits on the production cross-section between 0.05 and 0.19 pb have been derived for scalar and spin-1/2 particles with charge +/-1. Within the framework of the minimal supersymmetric model (MSSM), this implies a lower limit of 82.5 (83.5) GeV on the mass of long-lived right- (left-)handed scalar muons and scalar taus. Long-lived charged leptons and charginos are excluded for masses below 89.5 GeV. For particles with charge +/-2/3 the upper limits on the production cross-section vary between 0.05 and 0.2 pb. All limits, on masses and on cross-sections, are valid at the 95% confidence level for particles with lifetimes longer than 10^{-6} s. A search for stable and long-lived massive particles of electric charge |Q/e| = 1 or 2/3, pair-produced in e+e- collisions at centre-of-mass energies from 130 to 183 GeV, is reported by the OPAL collaboration at LEP. No evidence for production of these particles was observed in a mass range between 45 and 89.5 GeV. Model-independent upper limits on the production cross-section between 0.05 and 0.19 pb have been derived for scalar and spin-1/2 particles with charge +/-1. Within the framework of the minimal supersymmetric model (MSSM), this implies a lower limit of 82.5 (83.5) GeV on the mass of long-lived right- (left-)handed scalar muons and scalar taus. Long-lived charged leptons and charginos are excluded for masses below 89.5 GeV. For particles with charge +/-2/3 the upper limits on the production cross-section vary between 0.05 and 0.2 pb. All limits, on masses and on cross-sections, are valid at the 95% confidence level for particles with lifetimes longer than 10^{-6} s. A search for stable and long-lived massive particles of electric charge |Q/e| = 1 or 2/3, pair-produced in e+e- collisions at centre-of-mass energies from 130 to 183 GeV, is reported by the OPAL collaboration at LEP. No evidence for production of these particles was observed in a mass range between 45 and 89.5 GeV. Model-independent upper limits on the production cross-section between 0.05 and 0.19 pb have been derived for scalar and spin-1/2 particles with charge +/-1. Within the framework of the minimal supersymmetric model (MSSM), this implies a lower limit of 82.5 (83.5) GeV on the mass of long-lived right- (left-)handed scalar muons and scalar taus. Long-lived charged leptons and charginos are excluded for masses below 89.5 GeV. For particles with charge +/-2/3 the upper limits on the production cross-section vary between 0.05 and 0.2 pb. All limits, on masses and on cross-sections, are valid at the 95% confidence level for particles with lifetimes longer than 10^{-6} s. A search for stable and long-lived massive particles of electric charge |Q/e| = 1 or 2/3, pair-produced in e+e- collisions at centre-of-mass energies from 130 to 183 GeV, is reported by the OPAL collaboration at LEP. No evidence for production of these particles was observed in a mass range between 45 and 89.5 GeV. Model-independent upper limits on the production cross-section between 0.05 and 0.19 pb have been derived for scalar and spin-1/2 particles with charge +/-1. Within the framework of the minimal supersymmetric model (MSSM), this implies a lower limit of 82.5 (83.5) GeV on the mass of long-lived right- (left-)handed scalar muons and scalar taus. Long-lived charged leptons and charginos are excluded for masses below 89.5 GeV. For particles with charge +/-2/3 the upper limits on the production cross-section vary between 0.05 and 0.2 pb. All limits, on masses and on cross-sections, are valid at the 95% confidence level for particles with lifetimes longer than 10^{-6} s. A search for stable and long-lived massive particles of electric charge | Q / e |=1 or 2/3, pair-produced in e + e − collisions at centre-of-mass energies from 130 to 183 GeV, is reported by the OPAL collaboration at LEP. No evidence for production of these particles was observed in a mass range between 45 and 89.5 GeV. Model-independent upper limits on the production cross-section between 0.05 and 0.19 pb have been derived for scalar and spin-1/2 particles with charge ±1. Within the framework of the minimal supersymmetric model (MSSM), this implies a lower limit of 82.5 (83.5) GeV on the mass of long-lived right- (left-)handed scalar muons and scalar taus. Long-lived charged leptons and charginos are excluded for masses below 89.5 GeV. For particles with charge ±2/3 the upper limits on the production cross-section vary between 0.05 and 0.2 pb. All limits, on masses and on cross-sections, are valid at the 95% confidence level for particles with lifetimes longer than 10 −6 s.
Published: 1998

20. Measurement of the Photon Structure Function F_2^gamma at Low x

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, T. Barillari, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, C. Beeston, T. Behnke, A.N. Bell, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, J.E. Bloomer, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, B.T. Bouwens, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, R. Davies, S. De Jong, L.A. del Pozo, K. Desch, B. Dienes, M.S. Dixit, E. do Couto e Silva, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, J.E.G. Edwards, P.G. Estabrooks, H.G. Evans, M. Evans, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, D.G. Fong, M. Foucher, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, D.E. Hutchcroft, P. Igo-Kemenes, D.C. Imrie, M.R. Ingram, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, G. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, G. Mikenberg, D.J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, M. Morii, U. Müller, S. Mihara, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, N.J. Oldershaw, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, M.J. Pearce, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, D.L. Rees, D. Rigby, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, E. Ros, A.M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R. Rust, R. Rylko, K. Sachs, T. Saeki, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, P. Schenk, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, H.C. Schultz-Coulon, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, P. Szymanski, R. Tafirout, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, P. Utzat, R. Van Kooten, M. Verzocchi, P. Vikas, E.H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, B. Wilkens, G.W. Wilson, J.A. Wilson, G. Wolf, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Nuclear and High Energy Physics, Particle physics, Logarithm, FOS: Physical sciences, Generator, 01 natural sciences, Q2, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, 010306 general physics, Physics, Range (particle radiation), Luminosity (scattering theory), Parton Distributions, 010308 nuclear & particles physics, Scattering, Detector, Virtual Photons, LEP, Beam electron, Photon structure function, High Energy Physics::Experiment, Atomic physics, Particle Physics - Experiment
Abstract: Deep inelastic electron-photon scattering is studied using e+e- data collected by the OPAL detector at centre-of-mass energies sqrt{s_ee} ~ M_{Z^0}. The photon structure function F_2^gamma(x,Q^2) is explored in a Q^2 range of 1.1 to 6.6 GeV/c^2 at lower x values than ever before. To probe this kinematic region events are selected with a beam electron scattered into one of the OPAL luminosity calorimeters at scattering angles between 27 and 55 mrad. A measurement is presented of the photon structure function F_2^gamma(x,Q^2) at = 1.86 GeV^2 and 3.76 GeV^2 in five logarithmic x bins from 0.0025 to 0.2., Comment: 13 pages, LaTeX, uses a4p.sty, 3 eps figures included, submitted to Phys. Lett. B
Published: 1997

21. Spin alignment of leading $K^{*}(892)^{0}$ mesons in hadronic $Z^0$ decays

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, T. Barillari, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, C. Beeston, T. Behnke, A.N. Bell, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, J.E. Bloomer, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, B.T. Bouwens, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, K. Desch, B. Dienes, M.S. Dixit, E. do Couto e Silva, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, J.E.G. Edwards, P.G. Estabrooks, H.G. Evans, M. Evans, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, D.G. Fong, M. Foucher, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, D.E. Hutchroft, P. Igo-Kemenes, D.C. Imrie, M.R. Ingram, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, G. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, G. Mikenberg, D.J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, M. Morii, U. Müller, S. Mihara, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, N.J. Oldershaw, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, M.J. Pearce, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, D.L. Rees, D. Rigby, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, E. Ros, A.M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R. Rust, R. Rylko, K. Sachs, T. Saeki, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, P. Schenk, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, H.C. Schultz-Coulon, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, P. Szymanski, R. Tafirout, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, P. Utzat, R. Van Kooten, M. Verzocchi, P. Vikas, E.H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, B. Wilkens, G.W. Wilson, J.A. Wilson, G. Wolf, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Density matrix, Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Hadron, FOS: Physical sciences, 01 natural sciences, Helicity, High Energy Physics - Experiment, Standard Model, Momentum, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, Spin-½, Bar (unit)
Abstract: Helicity density matrix elements for inclusive K*(892)^0 mesons from hadronic Z^0 decays have been measured over the full range of K^*0 momentum using data taken with the OPAL experiment at LEP. A preference for occupation of the helicity zero state is observed at all scaled momentum x_p values above 0.3, with the matrix element rho_00 rising to 0.66 +/- 0.11 for x_p > 0.7. The values of the real part of the off-diagonal element rho_1-1 are negative at large x_p, with a weighted average value of -0.09 +/- 0.03 for x_p > 0.3, in agreement with new theoretical predictions based on Standard Model parameters and coherent fragmentation of the qq(bar) system from the Z^0 decay. All other helicity density matrix elements measured are consistent with zero over the entire x_p range. The K^*0 fragmentation function has also been measured and the total rate determined to be 0.74 +/- 0.02 +/- 0.02 K*(892)^0 mesons per hadronic Z^0 decay., 19 pages, LaTeX, uses a4p.sty, pennames.sty, 4 eps figures included, submitted to Phys. Lett. B
Published: 1997

22. Measurements with photonic events in e+e- collisions at centre-of-mass energies of 130-140 GeV

Author: G. Alexander, J. Allison, N. Altekamp, K. Ametewee, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, G. Beaudoin, J. Bechtluft, C. Beeston, T. Behnke, A.N. Bell, K.W. Bell, G. Bella, S. Bentvelsen, P. Berlich, S. Bethke, O. Biebel, V. Blobel, I.J. Bloodworth, J.E. Bloomer, P. Bock, H.M. Bosch, M. Boutemeur, B.T. Bouwens, S. Braibant, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, C. Charlesworth, D.G. Charlton, D. Chrisman, S.L. Chu, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, C. Darling, S. De Jong, L.A. del Pozo, M.S. Dixit, E. do Couto e Silva, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, J.E.G. Edwards, P.G. Estabrooks, H.G. Evans, M. Evans, F. Fabbri, P. Fath, F. Fiedler, M. Fierro, H.M. Fischer, R. Folman, D.G. Fong, M. Foucher, H. Fukui, A. Fürtjes, P. Gagnon, A. Gaidot, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, S.W. Gensler, F.X. Gentit, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, T. Hilse, P.R. Hobson, R.J. Homer, A.K. Honma, D. Horváth, R. Howard, R.E. Hughes-Jones, D.E. Hutchcroft, P. Igo-Kemenes, D.C. Imrie, M.R. Ingram, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, G. Jones, M. Jones, R.W.L. Jones, U. Jost, P. Jovanovic, J. Kanzaki, D. Karlen, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. King, J. Kirk, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, S. Komamiya, R. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, H. Lafoux, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, J.G. Layter, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, C. Lewis, S.L. Lloyd, F.K. Loebinger, G.D. Long, B. Lorazo, M.J. Losty, J. Ludwig, A. Luig, A. Malik, M. Mannelli, S. Marcellini, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, W. Matthews, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, A.I. McNab, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, M. Morii, U. Müller, B. Nellen, B. Nijjhar, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, T. Omori, M.J. Oreglia, S. Orito, M. Palazzo, J. Pálinkás, J.P. Pansart, G. Pásztor, J.R. Pater, G.N. Patrick, M.J. Pearce, S. Petzold, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, H. Przysiezniak, D.L. Rees, D. Rigby, M.G. Rison, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, E. Ros, A.M. Rossi, M. Rosvick, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, R. Rylko, E.K.G. Sarkisyan, M. Sasaki, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, P. Schenk, B. Schmitt, M. Schröder, H.C. Schultz-Coulon, M. Schulz, P. Schütz, J. Schwiening, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, T.J. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, A. Stahl, M. Starks, K. Stephens, J. Steuerer, B. Stockhausen, D. Strom, F. Strumia, P. Szymanski, R. Tafirout, H. Takeda, P. Taras, S. Tarem, M. Tecchio, N. Tesch, M. Thiergen, M.A. Thomson, E. von Törne, S. Towers, M. Tscheulin, E. Tsur, A.S. Turcot, M.F. Turner-Watson, P. Utzat, R. Van Kooten, G. Vasseur, M. Verzocchi, P. Vikas, M. Vincter, E.H. Vokurka, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, J.J. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P. Weber, P.S. Wells, N. Wermes, J.S. White, B. Wilkens, G.W. Wilson, J.A. Wilson, T. Wlodek, G. Wolf, S. Wotton, T.R. Wyatt, S. Xella, S. Yamashita, G. Yekutieli, K. Yoshimura, and V. Zacek
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Photon, Mass distribution, business.industry, Electron–positron annihilation, Resonance, law.invention, Standard Model, Nuclear physics, law, Excited state, High Energy Physics::Experiment, Photonics, business, Collider, Particle Physics - Experiment
Abstract: Cross-sections and angular distributions for the production of events with single and multiple photons are measured from data recorded with the OPAL detector at the recently upgraded LEP collider. The measured cross-sections are generally consistent with Standard Model expectations for the e + e − → ν v γ(γ) and e+e− → γγ(γ) processes. Six events with an acoplanar photon pair and large missing mass are found. The observed number of events is larger than expected from e + e − → ν ν γγ ; however, the missing mass distribution is compatible with the Z0 resonance. Deviations from QED are constrained by the data on e+e− → γγ(γ). Lower limits are set at 95% confidence level on the QED cut-off parameters Λ+ and Λ− of 152 GeV and 142 GeV, respectively, and also on the mass of an excited electron of 147 GeV.
Published: 1996

23. elastic scattering at 30 GeV/c incident momentum in the momentum trasfer range 0.5<−t<5.8(GeV/c)2

Author: L. Bugge, J.P. Guillaud, J. Myrheim, A. Lundby, I. Kenyon Gjerpe, F.F. Heymann, R. K. Bock, M. M. Macri, L. Rossi, V. Gracco, A. Santroni, K. Kirsebom, C. Baglin, D.G. Davis, B.G. Duff, D. Skjevling, M. Coupland, G.J. Lush, J.M. Brom, T. Buran, D.C. Imrie, S.O. Sørensen, E. Khan, S. Ferroni, A. Buzzo, M. Poulet, Z. Asa'd, T. Fearnley, and Mark Phillips
Subjects: Physics, Scattering cross-section, Elastic scattering, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Momentum (technical analysis), Range (particle radiation), Large Hadron Collider, Spectrometer, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Nuclear Experiment
Abstract: The p p elastic differential cross section at 30 GeV/c incident momentum has been measured in a two-arm spectrometer experiment (WA7) at the CERN SPS. The |t|-range covered extends from 0.5 to 5.8 (GeV/c)2. A pronounced dip-bump structure is observed, with a sharp minimum around |t| ≈ 1.7 (GeV/c)2. The results are compared with existing p p data at lower energies and with our earlier p p data at 50 GeV/c. A number of model predictions are discussed. We also compare the p p 30 GeV/c differential cross section with that of pp at the same momentum. Finally, the energy dependence of the p p fixed-|t| differential cross in the incident momentum range 3.6 to 50 GeV/c is presented.
Published: 1983

24. The double associated production of charmed particles by the interaction of 350 mesons with emulsion nuclei

Author: G. Rosa, H. Tajima, M. Hazama, G. Crosetti, Shigeki Aoki, M. J. Esten, K. Chiba, Shigeki Tasaka, M. Barth, Franco Meddi, Luciano Ramello, Makoto Kobayashi, M. Miyanishi, K. Nakazawa, C. Sgarbi, J. H. Bartley, K. Niu, L. Riccati, M. Kazuno, M. T. Muciaccia, F.F. Heymann, Salvatore Nuzzo, S. Natali, K. Hoshino, K. Kodama, R. Roosen, F. Piuz, G. Bertrand-Coremans, A.C. Breslin, I. Tezuka, M. Coupland, A. Marzari-Chiesa, G. Baroni, F. Minakawa, Giovanni Carboni, Y. Yanagisawa, Y. Tsuneoka, H. Sletten, O. Yamakawa, D.H. Davis, G.J. Lush, Y. Isokane, M.A. Mazzoni, S. Simone, P. Musset, A. Montwill, A. Manfredini, D.C. Imrie, P. T. Trent, Y. Sato, V. Bisi, N. Ushida, E. Chesi, R. Arnold, Y. Maeda, F. Ruggieri, Paolo Giubellino, S. Dell'Uomo, G. Romano, S. Di Liberto, D. Gamba, W. Donnelly, Y. Tomita, C. Gerke, H. Sasaki, Gilbert Poulard, K. Niwa, H. Shibuya, D.N. Tovee, M. Ohashi, Mitsuhiro Nakamura, Heyd, Yvette, Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), and WA76
Subjects: Physics, Nuclear and High Energy Physics, Muon, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], Meson, double charm production, CERN SpS, nuclear emulsions, Nuclear physics, Momentum, Emulsion, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Pi, Beam direction, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract: Evidence is reported for the simultaneous production of four charmed particles in interactions induced by 350 GeV/ c π − mesons in stacks of nuclear emulsions. The events were found during a search for beauty particles among a sample of about 200 interactions with candidates for charmed particles. The events selected required the presence of at least one muon with a high component of momentum transverse to the beam direction.
Published: 1987

25. K−p elastic scattering between 1.73 GeV/c and 2.47 GeV/c

Author: P.R. Pitts, G.J. Lush, B.G. Duff, S.J. Sharrock, K.M. Potter, D.C. Imrie, R.C. Hanna, P.C. Barber, R.A. Rosner, E.N. Mgbenu, A.D. Smith, T.A. Broome, E.J. Sacharidis, L.A. Robbins, and F.F. Heymann
Subjects: Physics, Elastic scattering, Nuclear and High Energy Physics, Antiparticle, Particle physics, Meson, Scattering, Nuclear Theory, Hadron, Baryon, Antimatter, High Energy Physics::Experiment, Nuclear Experiment, Nucleon
Abstract: Differential cross sections for the elastic scattering of negative kaons on protons are presented for 19 momenta between 1.732 GeV/c and 2.466 GeV/c. The general features of the cross sections are discussed.
Published: 1976

26. Drift chambers

Author: D.C Imrie
Subjects: History and Philosophy of Science
Published: 1979

27. Proton-proton elastic scattering at 50 GeV/c incident momentum in the momentum transfer range 0.8<−t<4.0 (GeV/c)2

Author: S. Ferroni, L. Bugge, J.M. Brom, F.F. Heymann, G.J. Lush, T. Fearnley, Z. Asa'd, R. K. Bock, A. Lundby, B.G. Duff, G. Skjevling, T. Buran, I. Kenyon Gjerpe, D.C. Imrie, S.O. Sørensen, M. Poulet, M. Coupland, C. Baglin, Mark Phillips, A. Buzzo, K. Kirsebom, J.P. Guillaud, M. M. Macri, D.G. Davis, V. Gracco, J. Myrheim, A. Santroni, BOMBAR, Claudine, Laboratoire d'Annecy de Physique des Particules (LAPP), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)
Subjects: Scattering cross-section, Physics, Elastic scattering, Nuclear and High Energy Physics, Particle physics, Momentum (technical analysis), Range (particle radiation), [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], Proton, 010308 nuclear & particles physics, Momentum transfer, 7. Clean energy, 01 natural sciences, Nuclear physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment, 010306 general physics, Particle Physics - Experiment
Abstract: A measurement of the proton-proton elastic differential cross section at 50 GeV/ c incident momentum in the momentum transfer range 0.8 t | c ) 2 is presented. The data are compared to pp data at lower and higher energies, and to some model predictions.
Published: 1983

28. Hadroproduction of pairs in π− U interactions at 320 GeV energy

Author: P. Pistilli, B. Alessandro, W. Alpe, J.H. Bartley, W. Bisi, M.G. Catanesi, H. Cobbaert, J. Conboy, M. Coupland, G. Crosetti, M. De Vincenzi, S. Di Liberto, B.G. Duff, M.J. Esten, P. Fennel, M. Fidecaro, A. Frenkel, D. Gamba, P.F. Harrison, F.F. Heymann, D.C. Imrie, M. Iori, E. Lamanna, G. Marini, G. Martellotti, M.T. Muciaccia, P. Musset, S. Natali, A. Nigro, S. Nuzzo, A. Parisi, G. Penso, S. Petrera, E. Petrolo, G. Poulard, L. Ramello, L. Riccati, I.G. Roberts, G. Romano, R. Roosen, G. Rosa, F. Ruggieri, A. Sciubba, H. Sletten, and P.T. Trent
Subjects: Quantum chromodynamics, Nuclear physics, Physics, Nuclear and High Energy Physics, Muon, chemistry, Physics::Instrumentation and Detectors, chemistry.chemical_element, High Energy Physics::Experiment, Atomic physics, Uranium, Atomic and Molecular Physics, and Optics, Energy (signal processing)
Abstract: A signal from B B associated production in π − Uranium interactions at 320 GeV, has been observed looking at events with three muons and two like-sign muons in the final state. The experimental energy and p T distributions of muons as well as the total cross section are in good agreement with QCD predictions.
Published: 1988

29. Large-angle elastic scattering of charged pions on protons at 20 and 30 GeV/c incident momenta

Author: L. Causton, L. Bugge, G. Skjevling, M. Macri, T. Jacobsen, L. Rossi, R. Mollerud, R. Almas, P. Helgaker, A. Santroni, J. Haldorsen, K. Guettler, R. Lowndes, C. Baglin, K. Brobakken, D.G. Davis, A. Eide, M. Yvert, K.E. Johansson, E.T.C. Borggaard, H. Schwartz, A. Buzzo, J.D. Hansen, R. K. Bock, B. Schistad, M. Coupland, M. Poulet, S. Kooijman, J.P. Guillaud, S. Ferroni, K. Kirsebom, I. Gjerpe, B.G. Duff, J. Tavernier, F.F. Heymann, A. Lundby, P.J. Carlson, V. Gracco, J. Myrheim, T. Buran, D.C. Imrie, S.O. Sørensen, and G.J. Lush
Subjects: Physics, Nuclear physics, Elastic scattering, Nuclear and High Energy Physics, Pion, Atomic physics, Particle Physics - Experiment, Lower energy
Abstract: Elastic cross-section measurements are presented for π ± −p at 20 GeV/ c and π − −p at 30 GeV/ c incident momenta in the large angle region (50° to 90° in the c.m. system). The data are compared with published lower energy elastic cross sections. A test is made of the dimensional counting rules for π ± −p elastic scattering and some indication of a deviation from this rule is observed in the π − −p case. A comparison is also made with the predictions of the constituent interchange model. Although the broad features of the predictions are confirmed, there are some important discrepancies. Finally, the predictions of the model due to Preparata and Soffer are also compared with the new data.
Published: 1980

30. Experimental study of B production π-U interactions at 320 GeV energy

Author: J. H. Bartley, Salvatore Nuzzo, V. Bisi, F. Ruggieri, M. J. Esten, S. Petrera, A. Parisi, E. Lamanna, A. Nigro, G. Crosetti, M. De Vincenzi, Emilio Petrolo, H. Cobbaert, L. Ramello, F.F. Heymann, A. Frenkel, Gilbert Poulard, P. T. Trent, P. F. Harrison, M. Coupland, P. Pistilli, G. Rosa, W. Alpe, J. E. Conboy, M. T. Muciaccia, S. Natali, G. Romano, D.C. Imrie, L. Riccati, A. Sciubba, M. G. Catanesi, S. Di Liberto, M. Fidecaro, D. Gamba, M. Iori, Bruno Alessandro, P. Fennel, I. G. Roberts, G. Martellotti, G. Marini, Gianni Penso, H. Sletten, and R. Roosen
Subjects: Physics, Quantum chromodynamics, Nuclear physics, Nuclear and High Energy Physics, Cross section (physics), beauty particle production, CERN SpS, WA78, Mixing (physics)
Abstract: A sample of 29 gu+ υ+ 35 υ− υ− coming from B B decay have been observed in π-U interactions at 320 GeV energy. The experimental distributions and the total cross section are found to be in good agreement with QCD predictions. The effect of B0 B 0 mixing is discussed.
Published: 1988

31. Performance of a sampling calorimeter with alternate U and Fe absorbers

Author: J. H. Bartley, F.F. Heymann, A. Sciubba, M. De Vincenzi, A. Frenkel, Salvatore Nuzzo, M. Coupland, S. Di Liberto, P. T. Trent, D. Gamba, G. Rosa, G. Martellotti, P. Fennel, V. Bisi, G. Marini, M. Fidecaro, M. G. Catanesi, P. F. Harrison, M. T. Muciaccia, G. Crosetti, A. Nigro, M. J. Esten, R. Roosen, S. Petrera, H. Cobbaert, F. Ruggieri, G. Romano, B.G. Duff, H. Sletten, Gianni Penso, E. Lamanna, L. Riccati, D.C. Imrie, Gilbert Poulard, P. Pistilli, and L. Ramello
Subjects: Physics, Nuclear and High Energy Physics, Calorimeter (particle physics), Physics::Instrumentation and Detectors, business.industry, Hadron, Resolution (electron density), Sampling (statistics), Scintillator, Nuclear physics, Optics, hadron compensation, Homogeneous, sampling calorimeter, High Energy Physics::Experiment, Detectors and Experimental Techniques, cern sps, business, Instrumentation, Beam (structure)
Abstract: A sampling hadronic calorimeter, consisting of a sandwich of scintillator plates and alternate U and Fe absorbers, has been tested in a 135 GeV energy beam. The energy resolution turns out to be significantly improved with respect to the homogeneous configurations in which only U or Fe absorbers are used.
Published: 1986

32. A new approach to positron emission tomography

Author: Georges Charpak, Kevin Wells, J. Jeanjean, D.C. Imrie, P. Miné, H. Nguyen, D. Scigocki, and Stefaan Tavernier
Subjects: Wire chamber, medicine.diagnostic_test, Physics::Instrumentation and Detectors, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Physics::Medical Physics, Detector, Gamma ray, General Medicine, Scintillator, Optics, Positron emission tomography, Scintillation counter, medicine, Radiology, Nuclear Medicine and imaging, Tomography, Nuclear medicine, business, Emission computed tomography, Tomography, Emission-Computed
Abstract: A recently developed detection principle for gamma rays offers the prospect of improving the performance of positron emission tomographic scanners. This detection principle is based on the use of BaF2 scintillator and photosensitive wire chambers. We present technical results obtained with a prototype detector. It is shown that the impact point of the gamma ray can be determined with a precision of a few mm and that the detection efficiency is 60% with a time resolution of 10 ns (FWHM). A scanner based on the new principle is described and its anticipated performance discussed.
Published: 1989

33. THE USE OF COMPTON BACKSCATTER IMAGING FOR THE DETECTION OF CORROSION PITTING IN OFFSHORE STRUCTURES

Author: D.C. Imrie, B. Bridge, J.M. Gunnell, and N.J. Olson
Subjects: Engineering, Backscatter, business.industry, Acoustics, Detector, Gamma ray, Corrosion monitoring, Submarine pipeline, False alarm, Structural engineering, Underwater, business, Corrosion
Abstract: A mobile Compton backscatter imaging device 60 using a 10 Ci CO60 source is proposed for corrosion monitoring of underwater offshore oil risers, in the presence of marine growth or protective coatings. The design of a prototype detector system is presented and its performance evaluated in terms of the interdependence of scanning speed, defect volume and detection probability, and false alarm probability. An apparatus constructed to confirm some aspects of the design using a weak gamma ray source is described and first results on the observation of 6mm diameter voids in 22mm thick sections of mild steel, are given
Published: 1986

34. Development and operation of a multiwire proportional chamber system

Author: S.M. Fisher, J.K. Davies, D.C. Imrie, and G.J. Lush
Subjects: Wire chamber, Large Hadron Collider, Optics, Materials science, Physics::Instrumentation and Detectors, business.industry, Physics::Accelerator Physics, Proton Synchrotron, General Medicine, Electronics, Overall performance, business, Beam (structure)
Abstract: A multiwire proportional chamber system consisting of ten beam chambers and seven 0.5 m2 chambers, each with 2 mm wire spacing, has been developed and used in an experiment at the CERN proton synchrotron. The constructional details of chambers and electronics are described and the overall performance of the system is discussed.
Published: 1975

35. A Measurement of the Total Charm Cross Section in 200 and 360 GeV/c pN Interactions Using a Holographic Bubble Chamber

Author: M. Boratav, K. Geissler, F.F. Heymann, R. Roosen, D. Geiregat, Peter R Hobson, J L Bailly, B.G. Duff, N.G. Minaev, J. F. Baland, J. H. Bartley, A M Touchard, E Johansson, O. R. Williams, G Neuhofer, Salvatore Nuzzo, M. J. Esten, G.J. Lush, R. Arnold, Anton Taurok, Paul Lecoq, F. Ruggieri, H. Drevermann, M. Calicchio, Stefaan Tavernier, F. Grard, M. T. Muciaccia, R. Cranfield, M. Barth, G. Maurer, V. P. Henri, Alain Hervé, J Kesteman, I. Gjerpe, Josef Hrubec, S. Natali, M. Coupland, H. Cobbaert, O. Erriquez, M C Touboul, D.C. Imrie, P. Olivier, F. W. Bullock, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Particle physics, 010308 nuclear & particles physics, Topological information, Holography, Condensed Matter Physics, 01 natural sciences, Atomic and Molecular Physics, and Optics, law.invention, Nuclear physics, Cross section (physics), Pair production, law, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Bubble chamber, High Energy Physics::Experiment, Atomic number, Charm (quantum number), Liquid bubble, Nuclear Experiment, 010306 general physics, Particle Physics - Experiment, Mathematical Physics
Abstract: We present results from the first holographic bubble chamber experiment. Using topological information on the events observed in the heavy liquid bubble chamber HOBC, we have determined a total charm pair production cross section of (24.6-8.3+12.0) μb and (3.9-1.9+2.5) μb in 360 GeV/c and 200 GeV/c proton-nucleon interactions respectively. For these estimates we assumed a linear dependence of the charm cross section on the atomic number A.
Published: 1986

36. A comparative study of the dissociation of protons into low-mass pπ+π− systems in coherent and incoherent proton-nucleus collisions at 18.6 GeV/c

Author: S. Kullander, Tord Ekelof, J. Nassalski, P. Grafström, S.M. Fisher, P.C. Bruton, S. Jonsson, E. Hagberg, and D.C. Imrie
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, medicine.anatomical_structure, Proton, medicine, Atomic physics, Low Mass, Nucleus, Dissociation (chemistry), Particle Physics - Phenomenology
Abstract: A decay angular moments analysis has been performed on 8500 p π + π − events produced by the interaction of high-energy protons with nuclear targets. The analysis was carried out separately for the low- t , coherent events and high- t , incoherent events. The moments of the two samples show significant differences and possible reasons for such differences are discussed.
Published: 1977

37. An experimental study of large-angle elastic scattering of charged mesons and antiprotons on protons at 20 and 30 GeV/c incident momenta

Author: M. Macri, A. Lundby, B.G. Duff, R. Mollerud, E. Johansson, V. Gracco, J. Tavernier, C. Baglin, K. Brobakken, L. Rossi, R. Lowndes, G.J. Lush, A. Santroni, S. Kooijman, J.D. Hansen, A. Buzzo, L. Causton, D.G. Davis, J. Haldorsen, D.C. Imrie, J. Myrheim, T. Buran, M. Yvert, F.F. Heyman, P. Helgaker, S.O. Sørensen, R.B. Böck, G. Skjevling, M. Coupland, S. Ferroni, B. Schistad, M. Poulet, I. Kenyon-Gjerpe, P.J. Carlson, L. Bugge, J.P. Guillaud, and K. Kirsebom
Subjects: Physics, Elastic scattering, Nuclear and High Energy Physics, Particle physics, Annihilation, Meson, 010308 nuclear & particles physics, Scattering, Hadron, 01 natural sciences, Nuclear physics, Pion, Pair production, Antiproton, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract: A description is given of an experiment to study elastic scattering of π±, K±and p on protons at c.m. scattering angles from 45° to 100° at incident laboratory momenta 20 GeV/c and 30 GeV/c. The corresponding t range is from −6.2 (GeV/c)2 to −28 (GeV/c)2. There are no previous observations for these reactions in this t range. High intensity and large geometrical acceptance were required in order to measure the low cross sections. The experiment used a double-arm spectrometer. MWPCs were used for reconstruction, and threshold and differential Cerenkov counters for identification. Scintillation counters, Cerenkov counters and a hadron calorimeter were used in the trigger. The trigger logic utilized specially designed matrices and a hard wired microprocessor. The π−p elastic scattering cross sections follow approximately the dimensional counting rule from 3.5 GeV/c.and up to 30 GeV/c. The cross sections decrease by seven orders of magnitude in this energy range. The data is compared to quark models. None of these models give a comprehensive description of the results. However, some modifications to these models improve their consistency with the data.
Published: 1983

38. Elastic scattering and coherent single pion production in proton-helium interactions at 18.6 GeV/c

Author: C.S. Curran, F.F. Heymann, S. Kullander, P.C. Bruton, S.M. Fisher, A.L. Read, J.K. Davies, E. Hagberg, A.J. Herz, J. Nassalski, G.J. Lush, T. Ekelöf, and D.C. Imrie
Subjects: Nuclear physics, Physics, Elastic scattering, Nuclear and High Energy Physics, Pion, chemistry, chemistry.chemical_element, High Energy Physics::Experiment, Atomic physics, Impulse (physics), Nuclear Experiment, Glauber, Helium
Abstract: Proton-helium elastic scattering and coherent single-pion production have been studied at 18.6 GeV/ c in the four-momentum transfer region (−0.06, −0.17) GeV/ c 2 . The elastic t -distribution has a somewhat steeper slope than is predicted by the Glauber approximation. The invariant-mass distribution of the Nπ system agrees with the double Regge-pole model except at about 1.65 GeV/ c 2 where an enhancement presumably due to N ∗ resonances is seen. The model also predicts the correct magnitude of the slope for n π + α events. By using our cross sections at t ′ = −0.06 (GeV/ c ) 2 where the impulse approximation should be valid, the isospin-zero exchange elementary cross section for the n π + production is evaluated. The inelastic angular distributions are consistent with several spinparity states contributing at all Nπ masses.
Published: 1978

39. Observation of a dip at elastic scattering at 50 GeV/c

Author: G. Skjevling, T. Buran, D.C. Imrie, P. Helgaker, L. Rossi, S.O. Sørensen, K. Brobakken, I. Gjerpe, B.G. Duff, S. Benson, K.E. Johansson, A. Santroni, M. Poulet, S. Ferroni, C. Baglin, V. Gracco, M. Yvert, R. Lowndes, D.G. Davis, G.J. Lush, M. Coupland, J.D. Hansen, T. Jacobsen, Z. Asa'd, Mark Phillips, A. Lundby, R. K. Bock, A. Buzzo, F.F. Heymann, P.J. Carlson, J. Myrheim, L. Bugge, M. Macri, R. Mollerud, and K. Kirsebom
Subjects: Nuclear physics, Physics, Scattering cross-section, Elastic scattering, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Spectrometer, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Nuclear Experiment
Abstract: The p p elastic differential cross section at 50 GeV/c has been measured in a two-arm spectrometer experiment at the CERN SPS. The | t | range covered extends from 0.7 to 5 (GeV/c. A pronounced dip-bump structure is observed with a sharp minimum at | t | = 1.5 (GeV/ c ) 2 .
Published: 1982

40. K−p elastic scattering between 1094 MeV/c and 1377 MeV/c

Author: G.J. Lush, R.A. Rosner, E.N. Mgbenu, A.D. Smith, L.A. Robbins, F.F. Heymann, P.C. Barber, B.G. Duff, T.A. Broome, P.R. Pitts, D.C. Imrie, R.C. Hanna, E.J. Sacharidis, K.M. Potter, and S.J. Sharrock
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, Antiparticle, Meson, Scattering, Nuclear Theory, Hadron, Scattering length, Charged particle, Nuclear physics, Atomic physics, Nuclear Experiment, Nucleon
Abstract: Differential cross sections for elastic scattering of negative kaons on protons are presented for 13 incident laboratory momenta between 1094 MeV/c and 1377 MeV/c. The data show the characteristic forward diffraction-like peak and backward dip and are adequately described in shape by certain published partial-wave analyses of the N system.
Published: 1975

41. The holographic film scanning machine 'Chimaera'

Author: Peter R Hobson, D.C. Imrie, and G.J. Lush
Subjects: Physics, Nuclear and High Energy Physics, Large Hadron Collider, business.industry, Holography, Physics::Optics, Video camera, GeneralLiterature_MISCELLANEOUS, law.invention, Optics, law, Spatial reference system, Control system, Bubble chamber, business, Instrumentation, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: The design and construction of a computer controlled machine for scanning and measuring in-line holograms. The equipment was designed for holograms produced in the bubble chamber HOBC used in the experiment NA25 at CERN. The choice of optical system and video camera tubes is discussed. The control system is described briefly. The problems of scanning and measuring charmed particle decays recorded on holographic film are discussed, and the errors in the measured spatial coordinates are considered.
Published: 1985

42. Differential cross sections for elastic π−p scattering at 16 momenta between 996 MeV/c and 1342 MeV/c

Author: D.C. Imrie, E.J. Sacharidis, R.C. Hanna, F.F. Heymann, R.A. Rosner, E.N. Mgbenu, L.A. Robbins, A.D. Smith, G.J. Lush, P.R. Pitts, B.G. Duff, P.C. Barber, T.A. Broome, K.M. Potter, and S.J. Sharrock
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, Scattering, Nuclear Theory, Scattering length, Nuclear physics, Angular distribution, Pion, Physics::Accelerator Physics, Nuclear cross section, Atomic physics, Nuclear Experiment, Differential (mathematics)
Abstract: Differential cross sections for elastic scattering of negative pions on protons are presented for 16 momenta between 996 MeV/ c and 1342 MeV/ c . The cross sections are compared with the predictions from published phase-shift analyses.
Published: 1975

43. Direct observations of the decay of beauty particles into charm particles

Author: V. Bisi, I. Tesuka, K. Chiba, Motoaki Miyanishi, S. Natali, G. Romano, S. Dell'Uomo, V. Alpe, M. Ohashi, F. Piuz, F.F. Heymann, R. Arnold, A. Marzari-Chiesa, Y. Maeda, F. Ruggieri, J. H. Bartley, Franco Meddi, M. Hazama, Shigeki Aoki, C. Sgarbi, Kimio Niwa, A.C. Breslin, B.G. Duff, C. Gerke, G. Baroni, Y. Kodama, P. T. Trent, Y. Yanagisawa, K. Niu, Salvatore Nuzzo, G. Bertrand-Coremans, W. Bonnelly, Gilbert Poulard, Y. Tsuneoka, Yasuhiro Tomita, L. Riccati, M. A. Mazzoni, E. Chesi, M. Kazuno, M. Nakamura, Shigeki Tasaka, Luciano Ramello, Yoshihiro Sato, G. Rosa, M.J. Esten, N. Ushida, Giovanni Carboni, M. T. Muciaccia, Kazuma Nakazawa, A. Montwill, M. Barth, O. Yamakawa, G.J. Lush, Y. Isokane, D.H. Davis, Dn Tovee, G. Crosetti, M. Coupland, J. P. Albanese, G.S. Cook, R. Roosen, P. Musset, D.C. Imrie, K. Hoshino, H. Shibuya, S. Di Liberto, D. Gamba, H. Sasaki, S. Simone, D. Bertrand, H. Sletten, Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), and Heyd, Yvette
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Physics::Instrumentation and Detectors, media_common.quotation_subject, Direct observation, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Nuclear physics, Particle decay, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], nuclear emulsion, Muon spectrometer, Beauty, Physique des particules élémentaires, caer sps, beauty particle decay, High Energy Physics::Experiment, Nuclear emulsion, Charm (quantum number), Nuclear Experiment, Event (particle physics), Particle Physics - Experiment, media_common
Abstract: The associated production of a pair of beauty particles B- and B0 by a 350 GeV π- interaction has been observed in an emulsion target inserted in an array of silicon microstrip detectors. Both beauty particles decay into charm particles, both of which are also observed to decay in the emulsion. Two negative muons were identified and their momenta measured in a large muon spectrometer. One muon has a pT of 1.9 GeV/c and is associated with a beauty particle decay. The other, with a pT of 0.45 GeV/c is associated with a charm particle decay. The flight times of the two beauty particles are respectively (0.8 ± 0.1) × 10-13 s and (5+2 -1) × 10-13 s. Alternative interpretations of this event have negligible probability, 0, SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 1985

44. Measurement of the differential cross section in proton-proton scattering at 49.41 MeV

Author: G.J. Lush, L.A. Robbins, T.C. Griffith, C.J. Batty, and D.C. Imrie
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, Proton, Scattering, Nuclear Theory, Absorption cross section, Inelastic scattering, Nuclear physics, Cross section (physics), X-ray Raman scattering, Physics::Accelerator Physics, Nuclear cross section, Nuclear Experiment
Abstract: The differential cross section for proton-proton elastic scattering at 49.41 MeV has been measured at 30 angles between 13° and 90° (c.m.) with an absolute precision of 0.5% to 0.7% over most of the angular range. The 90° c.m. cross section is compared with other data near 50 MeV.
Published: 1967

45. Measurements of K+ p elastic scattering differential cross sections in the incident momentum range 1368 to 2259 MeV/c

Author: S.J. Sharrock, P.C. Barber, G.J. Lush, D.M. Ritson, D.C. Imrie, B.G. Duff, R.A. Rosner, E.J. Sacharidis, K.M. Potter, J.K. Davies, T.A. Broome, E.N. Mgbenu, W. Busza, A.D. Smith, R.C. Hanna, F.F. Heymann, P.R. Pitts, L.A. Robbins, and D.A. Garbutt
Subjects: Nuclear physics, Momentum, Physics, Elastic scattering, Nuclear and High Energy Physics, Range (particle radiation), Scattering, Scintillation counter, Scattering length, Legendre polynomials, Differential (mathematics)
Abstract: Measurements of complete angular distributions of elastic K + p scattering at closely spaced incident momenta from 1368 to 2259 MeV/ c are presented and discussed. A PDP-8 computer controlled system of scintillation counters and core-readout wire spark chambers was used for the detection of elastic events. Diffractive behaviour is already present at the lowest measured momentum and becomes more prominent as the incident momentum increases. An expansion of the angular distributions in terms of Legendre polynomials shows no marked structure of the expansion coefficients as functions of the incident momentum. Our measurements can be adequately described by a number of existing phase shift solutions within 5% of their published values. Also Regge pole extrapolations represent our data satisfactorily.
Published: 1973

46. K+p elatic differential cross section measurements between 1.4 and 2.3 GeV/c and a phase shift analysis

Author: G.J. Lush, D.M. Ritson, F.F. Heymann, E.J. Sacharides, A.D. Smith, A.T. Lea, B.R. Martin, P.C. Barber, S.J. Sharrock, R.C. Hanna, R.A. Rosner, T.A. Broome, L.A. Robbins, K.M. Potter, D.C. Imrie, and B.G. Duff
Subjects: Nuclear physics, Elastic scattering, Momentum, Scattering cross-section, Physics, Nuclear and High Energy Physics, Atomic physics, Resonance (particle physics)
Abstract: The differential cross section for K+p elastic scattering has been measured at 26 momenta between 1.4 and 2.3 GeV/c. The data have been included in a phase shift analysis; four solutions have been found, none of which requires the existence of a Z 1 ∗ resonance.
Published: 1970

47. Elastic scattering of charged mesons, antiprotons and protons on protons at incident momenta of 20, 30 and 50 GeV/c in the momentum transfer range $0.5 < -t < 8 (GeV/c)^{2}$

Author: Mark Phillips, K. Kirsebom, L. Bugge, G. Skjevling, B.G. Duff, G.J. Lush, F.F. Heymann, M. Poulet, C. Baglin, S. Ferroni, I. Kenyon Gjerpe, J.P. Guillaud, M. M. Macri, V. Gracco, T. Buran, J. Myrheim, D.C. Imrie, A. Lundby, Z. Asa'd, A. Buzzo, A. Santroni, T. Fearnley, M. Coupland, T. Sorsdal, D.G. Davis, and R. K. Bock
Subjects: Quantum chromodynamics, Elastic scattering, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Large Hadron Collider, Meson, Scattering, Momentum transfer, Nuclear physics, Antiproton, Nuclear Experiment, Particle Physics - Experiment
Abstract: Results are presented from experiment WA7 at the CERN SPS, which has measured the elastic differential cross sections of π±p, K±p, pp and pp at incident momen ta of 20, 30 and 50 GeV/c. The measurements cover the momentum transfer range 0.5 < |t| < 8 (GeV/c)2, corresponding to c.m. scattering angles between 10° and 50°. The experimental set-up, trigger logic and data analysis are described. The experimental results are compared with existing meson-proton and nucleon-proton data at lower and higher energies covering the medium- and large-|t| region. Some prominent models and their predictions for elastic scattering at WA7 energies and beyond are reviewed, with emphasis on geometrical scaling, factorizing eikonal models, lowest-order QCD and other dynamical exchange-type models. Results for pp two-body annihilation into π−π+ and K−K+ at 30 and 50 GeV/c, obtained in parallel with the elastic pp data, are also presented.
Published: 1984

48. Experimental study of uranium-scintillator and iron-scintillator calorimetry in the energy range 135-350 GeV

Author: M. De Vincenzi, D.C. Imrie, G. Crosetti, P. Pistilli, H. Sletten, F. Ruggieri, D. Gamba, B.G. Duff, Gilbert Poulard, Gianni Penso, Adalberto Sciubba, M. Coupland, G. Marini, H. Cobbaert, L. Ramello, G. Martellotti, A. Nigro, F. Bronzini, A. Frenkel, R. Roosen, M. G. Catanesi, and M. J. Esten
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), Astrophysics::High Energy Astrophysical Phenomena, Hadron, chemistry.chemical_element, Calorimetry, Scintillator, Uranium, Calorimeter, Nuclear physics, chemistry, High Energy Physics::Experiment, Detectors and Experimental Techniques, Nuclear Experiment, Instrumentation, Energy (signal processing)
Abstract: Results are reported of measurements made using a sampling hadronic calorimeter in the energy range 135–350 GeV. The responses to hadronic showers at various energies using iron and uranium of different thicknesses as absorbers have been compared. The results obtained in iron are in substantial agreement with the existing data, while those in uranium show an unexpected overcompensation in the hadronic response. Direct measurement of the e π ratio is in agreement with this statement.
Published: 1985

49. The production of beauty particles in $\pi-U$ interactions at 320 GeV energy

Author: G. Martellotti, D.C. Imrie, M. Fidecaro, F. Ruggieri, Emilio Petrolo, Gianfranca De Rosa, A. Sciubba, H. Sletten, A. Frenkel, I. G. Roberts, M. Coupland, S. Di Liberto, D. Gamba, L. Riccati, Gilbert Poulard, W. Alpe, M. J. Esten, J. E. Conboy, M. T. Muciaccia, Bruno Alessandro, V. Bisi, Gianni Penso, G. Marini, H. Cobbaert, A. Nigro, A. Parisi, G. Romano, P. F. Harrison, E. Lamanna, F.F. Heymann, M. G. Catanesi, P. Musset, L. Ramello, B.G. Duff, P. Fennel, P. T. Trent, S. Petrera, P. Pistilli, G. Crosetti, S. Natali, M. De Vincenzi, J. H. Bartley, Salvatore Nuzzo, and R. Roosen
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, chemistry.chemical_element, State (functional analysis), Uranium, Nuclear physics, Cross section (physics), chemistry, Production (computer science), Nucleon, Beam energy, Particle Physics - Experiment
Abstract: B B production in π − -uranium interactions has been observed at 320 GeV beam energy looking at events with three muons in the final state. The cross section is found to be σ B B = 4.5±1.4±1.4 nb per nucleon (for a linear A -dependence) or σ B B = 17.6±5.5±5.5 nb per nucleon (assuming A 0.75 dependence). An estimate of x F distribution is given.
Published: 1986

50. The holographic bubble chamber experiment and the determination of the effective charmed quark mass and the K-factor for hadronic charm production

Author: Fernand Grard, V. P. Henri, E. Johannsson, J. H. Bartley, R. Arnold, Alain Hervé, D. Geiregat, F. Ruggieri, H. Cobbaert, G. Neuhofer, J. F. Balland, Salvatore Nuzzo, F. W. Bullock, J. L. Bailly, Josef Hrubec, F.F. Heymann, O. Erriquez, Peter R Hobson, D.C. Imrie, Paul Lecoq, G. Maurer, P. Olivier, M. T. Muciaccia, K. Geissler, M. Barth, H. Drevermann, Stefaan Tavernier, M. Callichio, S. Natali, M. J. Esten, M. Coupland, B.G. Duff, M. C. Touboul, J. Kesteman, R. Roosen, G.J. Lush, A.-M. Touchard, M. Boratav, Anton Taurok, O. R. Williams, Heyd, Yvette, Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Quantum chromodynamics, Particle physics, Annihilation, Physics and Astronomy (miscellaneous), [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], Hadron, Gluon, Charm quark, Nuclear physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Bubble chamber, Charm (quantum number), Atomic number, Engineering (miscellaneous), Particle Physics - Experiment
Abstract: In the first holographic bubble chamber experiment — the HOBC experiment — we have accumulated a total of 40000 holograms with particle interactions. We have determined the total charm pair cross section inpN collisions to be 23.3−7.7+10 μb and 3.6−1.7+2.3 μb for 360 and 200 GeV/c incident protons respectively. We have assumed a linear dependence of the cross section on the atomic number of the target. This experiment has demonstrated the feasibility of holographic recording in small bubble chambers. Assuming that the charm cross section can be described by the standard QCD factorized expression with gluon fusion and quark-antiquark annihilation, we have used our measured charm cross sections with other measurements to determine the effective charmed quark mass to be 1.8−0.35+0.25 GeV/c2. TheK factor, which describes the importance of the higher order corrections, is calculated to be 9.8−6.9+12.5 (See noted added in proof.)
Published: 1987

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