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76 results on '"R.J. Hemingway"'

1. NON-STRANGE VECTOR-MESON PRODUCTION IN K-P INTERACTIONS AT 4.2 GEV-C

Author

S-O. Holmgren, G. G.G. Massaro, R.P. Worden, B. Foster, Joris S. M. Vergeest, Jon-Paul R. Wells, Louis Lyons, R. Blokzijl, M.J. Losty, P. Grossmann, R.J. Hemingway, R. T. Van de Walle, J. Timmermans, Fernando Barreiro, J.C. Kluyver, G.F. Wolters, and Manuel Aguilar-Benitez

Subjects
Physics, Density matrix, Nuclear and High Energy Physics, Particle physics, Hypercharge, High Energy Physics::Phenomenology, Momentum transfer, Quark model, Hyperon, Nuclear physics, Amplitude, Bubble chamber, High Energy Physics::Experiment, Vector meson, Nuclear Experiment, Particle Physics - Experiment
Abstract

The vector meson production, hypercharge exchange reactions K/sup -/p to ( phi , omega , rho ) Lambda and ( phi , rho ) Sigma /sup 0/ are studied at 4.2 GeV/c incident momentum. The data come from a high statistics bubble chamber experiment with a sensitivity of approximately 120 events/ mu b. Total and differential cross sections are presented. The vector meson density matrix elements and hyperon polarization are investigated as functions of momentum transfer. Amplitude analyses are performed for all five reactions. The results are compared with duality and quark model predictions, as well as used to test current ideas in two-body phenomenology. (35 refs).

Published
2016

2. A measurement of the τ−→μ−ν̄μντ branching ratio

Author

G Abbiendi, C Ainsley, P.F Åkesson, G Alexander, J Allison, P Amaral, G Anagnostou, K.J Anderson, S Arcelli, S Asai, D Axen, G Azuelos, I Bailey, E Barberio, R.J Barlow, R.J Batley, P Bechtle, T Behnke, K.W Bell, P.J Bell, G Bella, A Bellerive, G Benelli, S Bethke, O Biebel, I.J Bloodworth, O Boeriu, P Bock, D Bonacorsi, M Boutemeur, S Braibant, L Brigliadori, R.M Brown, K Buesser, H.J Burckhart, S Campana, R.K Carnegie, B Caron, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, A Csilling, M Cuffiani, S Dado, S Dallison, A De Roeck, E.A De Wolf, K Desch, B Dienes, M Donkers, J Dubbert, E Duchovni, G Duckeck, I.P Duerdoth, E Elfgren, E Etzion, F Fabbri, L Feld, P Ferrari, F Fiedler, I Fleck, M Ford, A Frey, A Fürtjes, P Gagnon, J.W Gary, G Gaycken, C Geich-Gimbel, G Giacomelli, P Giacomelli, M Giunta, J Goldberg, E Gross, J Grunhaus, M Gruwé, P.O Günther, A Gupta, C Hajdu, M Hamann, G.G Hanson, K Harder, A Harel, M Harin-Dirac, M Hauschild, J Hauschildt, C.M Hawkes, R Hawkings, R.J Hemingway, C Hensel, G Herten, R.D Heuer, J.C Hill, K Hoffman, R.J Homer, D Horváth, R Howard, P Igo-Kemenes, K Ishii, H Jeremie, P Jovanovic, T.R Junk, N Kanaya, J Kanzaki, G Karapetian, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, R.K Keeler, R.G Kellogg, B.W Kennedy, D.H Kim, K Klein, A Klier, S Kluth, T Kobayashi, M Kobel, S Komamiya, L Kormos, T Krämer, T Kress, P Krieger, J von Krogh, D Krop, K Kruger, T Kuhl, M Kupper, G.D Lafferty, H Landsman, D Lanske, J.G Layter, A Leins, D Lellouch, L Levinson, J Lillich, S.L Lloyd, F.K Loebinger, J Lu, J Ludwig, A Macpherson, W Mader, S Marcellini, T.E Marchant, A.J Martin, J.P Martin, G Masetti, T Mashimo, W.J McDonald, J McKenna, T.J McMahon, R.A McPherson, F Meijers, P Mendez-Lorenzo, W Menges, F.S Merritt, H Mes, A Michelini, S Mihara, G Mikenberg, D.J Miller, S Moed, W Mohr, T Mori, A Mutter, K Nagai, I Nakamura, H.A Neal, R Nisius, S.W O'Neale, A Oh, A Okpara, M.J Oreglia, S Orito, C Pahl, G Pásztor, J.R Pater, G.N Patrick, J.E Pilcher, J Pinfold, D.E Plane, B Poli, J Polok, O Pooth, M Przybycień, A Quadt, K Rabbertz, C Rembser, P Renkel, H Rick, J.M Roney, S Rosati, Y Rozen, K Runge, K Sachs, T Saeki, O Sahr, E.K.G Sarkisyan, A.D Schaile, O Schaile, P Scharff-Hansen, J Schieck, T Schörner-Sadenius, M Schröder, M Schumacher, C Schwick, W.G Scott, R Seuster, T.G Shears, B.C Shen, P Sherwood, G Siroli, A Skuja, A.M Smith, R Sobie, S Söldner-Rembold, F Spano, A Stahl, K Stephens, D Strom, R Ströhmer, S Tarem, M Tasevsky, R.J Taylor, R Teuscher, M.A Thomson, E Torrence, D Toya, P Tran, T Trefzger, A Tricoli, I Trigger, Z Trócsányi, E Tsur, M.F Turner-Watson, I Ueda, B Ujvári, B Vachon, C.F Vollmer, P Vannerem, M Verzocchi, H Voss, J Vossebeld, D Waller, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, T Wengler, N Wermes, D Wetterling, G.W Wilson, J.A Wilson, G Wolf, T.R Wyatt, S Yamashita, D Zer-Zion, L Zivkovic, J Letts, P Mättig, and OPAL Collaboration

Subjects
Physics, Coupling constant, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Branching fraction, High Energy Physics::Phenomenology, 01 natural sciences, Nuclear physics, 0103 physical sciences, Higgs boson, High Energy Physics::Experiment, 010306 general physics, Lepton, Minimal Supersymmetric Standard Model
Abstract

The tau -> mu nu nu branching ratio has been measured using data collected from 1990 to 1995 by the OPAL detector at the LEP collider. The resulting value of B(tau -> mu nu nu) = 0.1734 +- 0.0009(stat) +- 0.0006(syst) has been used in conjunction with other OPAL measurements to test lepton universality, yielding the coupling constant ratios gmu/ge=1.0005+-0.0044 and gt/ge=1.0031+-0.0048, in good agreement with the Standard Model prediction of unity. A value for the Michel parameter eta = 0.004 +- 0.037 has also been determined and used to find a limit for the mass of the charged Higgs boson mH+- > 1.25 tan beta, in the Minimal Supersymmetric Standard Model.

Published
2003

3. Search for leptoquarks in electron–photon scattering at up to 209 GeV at LEP

Author

G. Abbiendi, C. Ainsley, P.F. Åkesson, G. Alexander, J. Allison, G. Anagnostou, K.J. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, I. Bailey, E. Barberio, R.J. Barlow, R.J. Batley, P. Bechtle, T. Behnke, K.W. Bell, P.J. Bell, G. Bella, A. Bellerive, G. Benelli, S. Bethke, O. Biebel, I.J. Bloodworth, O. Boeriu, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, S. Campana, R.K. Carnegie, B. Caron, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, P.E.L. Clarke, E. Clay, I. Cohen, J. Couchman, A. Csilling, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. De Roeck, E.A. De Wolf, P. Dervan, K. Desch, B. Dienes, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, E. Etzion, F. Fabbri, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, M. Giunta, J. Goldberg, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, A. Gupta, C. Hajdu, M. Hamann, G.G. Hanson, K. Harder, A. Harel, M. Harin-Dirac, M. Hauschild, J. Hauschildt, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, J.C. Hill, K. Hoffman, R.J. Homer, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, L. Kormos, R.V. Kowalewski, T. Krämer, T. Kress, P. Krieger, J. von Krogh, D. Krop, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, J. Lillich, C. Littlewood, S.L. Lloyd, F.K. Loebinger, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, G. Masetti, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, W. Menges, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, S. Moed, W. Mohr, T. Mori, A. Mutter, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, C. Pahl, G. Pásztor, J.R. Pater, G.N. Patrick, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, A. Quadt, K. Rabbertz, C. Rembser, P. Renkel, H. Rick, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, Y. Rozen, K. Runge, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, F. Spano, M. Sproston, A. Stahl, K. Stephens, D. Strom, R. Ströhmer, B. Surrow, S. Tarem, M. Tasevsky, R.J. Taylor, R. Teuscher, J. Thomas, M.A. Thomson, E. Torrence, D. Toya, T. Trefzger, A. Tricoli, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, B. Ujvári, B. Vachon, C.F. Vollmer, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, G.W. Wilson, J.A. Wilson, 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, High Energy Physics::Phenomenology, Scalar (mathematics), Supersymmetry, Electron, 01 natural sciences, First generation, Standard Model, 0103 physical sciences, High Energy Physics::Experiment, Leptoquark, 010306 general physics, Photon scattering
Abstract

Searches for first generation scalar and vector leptoquarks, and for squarks in R-parity violating SUSY models with the direct decay of the squark into Standard Model particles, have been performed using e+e- collisions collected with the OPAL detector at LEP at e+e- centre-of-mass energies between 189 and 209 GeV. No excess of events is found over the expectation from Standard Model background processes. Limits are computed on the leptoquark couplings for different values of the branching ratio to electron-quark final states.

Published
2002

4. Angular analysis of the muon pair asymmetry at LEP 1

Author

G. Abbiendi, C. Ainsley, P.F. Åkesson, G. Alexander, J. Allison, G. Anagnostou, K.J. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, I. Bailey, E. Barberio, R.J. Barlow, R.J. Batley, T. Behnke, K.W. Bell, P.J. Bell, G. Bella, A. Bellerive, S. Bethke, O. Biebel, I.J. Bloodworth, O. Boeriu, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, R.K. Carnegie, B. Caron, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, P.E.L. Clarke, E. Clay, I. Cohen, J. Couchman, A. Csilling, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. De Roeck, E.A. De Wolf, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, E. Etzion, F. Fabbri, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D. Glenzinski, J. Goldberg, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, A. Gupta, C. Hajdu, M. Hamann, G.G. Hanson, K. Harder, A. Harel, M. Harin-Dirac, M. Hauschild, J. Hauschildt, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, J.C. Hill, K. Hoffman, R.J. Homer, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, R.V. Kowalewski, T. Krämer, T. Kress, P. Krieger, J. von Krogh, D. Krop, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, J. Lillich, C. Littlewood, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, G. Masetti, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, W. Menges, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, S. Moed, W. Mohr, T. Mori, A. Mutter, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, C. Pahl, G. Pásztor, J.R. Pater, G.N. Patrick, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, A. Quadt, K. Rabbertz, C. Rembser, P. Renkel, H. Rick, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, Y. Rozen, K. Runge, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, F. Spano, M. Sproston, A. Stahl, K. Stephens, D. Strom, R. Ströhmer, L. Stumpf, B. Surrow, S. Tarem, M. Tasevsky, R.J. Taylor, R. Teuscher, J. Thomas, M.A. Thomson, E. Torrence, D. Toya, T. Trefzger, A. Tricoli, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, B. Ujvári, B. Vachon, C.F. Vollmer, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, D. Zer-Zion, G., Abbiendi, C., Ainsley, P. F., Akesson, G., Alexander, J., Allison, G., Anagnostou, K. J., Anderson, S., Arcelli, S., Asai, D., Axen, G., Azuelo, I., Bailey, E., Barberio, R. J., Barlow, R. J., Batley, T., Behnke, K. W., Bell, P. J., Bell, G., Bella, A., Bellerive, S., Bethke, O., Biebel, I. J., Bloodworth, O., Boeriu, P., Bock, J., Bohme, D., Bonacorsi, M., Boutemeur, S., Braibant, L., Brigliador, R. M., Brown, H. J., Burckhart, J., Cammin, R. K., Carnegie, B., Caron, A. A., Carter, J. R., Carter, C. Y., Chang, D. G., Charlton, P. E., L., E., Clay, I., Cohen, J., Couchman, A., Csilling, M., Cuffiani, S., Dado, G. M., Dallavalle, S., Dallison, A., De Roeck, E. A., De, P., Dervan, K., Desch, B., Diene, M. S., Dixit, M., Donker, J., Dubbert, E., Duchovni, G., Duckeck, I. P., Duerdoth, E., Etzion, F., Fabbri, L., Feld, P., Ferrari, F., Fiedler, I., Fleck, M., Ford, A., Frey, A., Furtje, D. I., Futyan, P., Gagnon, J. W., Gary, G., Gaycken, C., Geich Gimbel, G., Giacomelli, P., Giacomelli, D., Glenzinski, J., Goldberg, K., Graham, E., Gro, J., Grunhau, M., Gruwe, P. O., Gunther, A., Gupta, C., Hajdu, M., Hamann, G. G., Hanson, K., Harder, A., Harel, M., Harin Dirac, M., Hauschild, J., Hauschildt, C. M., Hawke, R., Hawking, R. J., Hemingway, C., Hensel, G., Herten, R. D., Heuer, J. C., Hill, K., Hoffman, R. J., Homer, D., Horvath, K. R., Hossain, R., Howard, P., Huntemeyer, P., Igo Kemene, K., Ishii, A., Jawahery, H., Jeremie, C. R., Jone, P., Jovanovic, T. R., Junk, N., Kanaya, J., Kanzaki, G., Karapetian, D., Karlen, V., Kartvelishvili, K., Kawagoe, T., Kawamoto, R. K., Keeler, R. G., Kellogg, B. W., Kennedy, D. H., Kim, K., Klein, A., Klier, S., Kluth, T., Kobayashi, M., Kobel, T. P., Kokott, S., Komamiya, R. V., Kowalewski, T., Kramer, T., Kre, P., Krieger, J., van Krogh, D., Krop, T., Kuhl, M., Kupper, P., Kyberd, G. D., Lafferty, H., Landsman, D., Lanske, I., Lawson, J. G., Layter, A., Lein, D., Lellouch, J., Lett, L., Levinson, J., Lillich, C., Littlewood, S. L., Lloyd, F. K., Loebinger, G. D., Long, M. J., Losty, J., Lu, J., Ludwig, A., Macchiolo, A., Macpherson, W., Mader, S., Marcellini, T. E., Marchant, A. J., Martin, J. P., Martin, G., Martinez, G., Masetti, T., Mashimo, P., Mattig, W. J., Mcdonald, J., Mckenna, T. J., Mcmahon, R. A., Mcpherson, F., Meijer, P., Mendez Lorenzo, W., Menge, F. S., Merritt, H., Me, A., Michelini, S., Mihara, G., Mikenberg, D. J., Miller, S., Moed, W., Mohr, T., Mori, A., Mutter, K., Nagai, I., Nakamura, H. A., Neal, R., Nisiu, S. W., O'Neale, A., Oh, A., Okpara, M. J., Oreglia, S., Orito, C., Pahl, G., Pasztor, J. R., Pater, G. N., Patrick, J. E., Pilcher, J., Pinfold, D. E., Plane, B., Poli, J., Polok, O., Pooth, A., Quadt, K., Rabbertz, C., Rembser, P., Renkel, H., Rick, N., Rodning, J. M., Roney, S., Rosati, K., Roscoe, Y., Rozen, K., Runge, D. R., Rust, K., Sach, T., Saeki, O., Sahr, E. K., G., C., Sbarra, A. D., Schaile, O., Schaile, P., Scharff Hansen, M., Schroder, M., Schumacher, C., Schwick, W. G., Scott, R., Seuster, T. G., Shear, B. C., Shen, C. H., Shepherd Themistocleou, P., Sherwood, A., Skuja, A. M., Smith, G. A., Snow, R., Sobie, S., Soldner Rembold, Spagnolo, Stefania Antonia, F., Spano, M., Sproston, A., Stahl, K., Stephen, D., Strom, R., Strohmer, L., Stumpf, B., Surrow, S., Tarem, M., Tasevsky, R. J., Taylor, R., Teuscher, J., Thoma, M. A., Thomson, E., Torrence, D., Toya, T., Trefzger, A., Tricoli, I., Trigger, Z., Trocsanyi, E., Tsur, M. F., Turner Watson, I., Ueda, B., Ujvari, B., Vachon, C. F., Vollmer, P., Vannerem, M., Verzocchi, H., Vo, J., Vossebeld, D., Waller, C. P., Ward, D. R., Ward, P. M., Watkin, A. T., Watson, N. K., Watson, P. S., Well, T., Wengler, N., Werme, D., Wetterling, G. W., Wilson, J. A., Wilson, T. R., Wyatt, S., Yamashita, V., Zacek, D., Zer Zion, and OPAL Collaboration

Subjects
Physics, Particle physics, Nuclear and High Energy Physics, Muon, 010308 nuclear & particles physics, media_common.quotation_subject, Photon radiation, FOS: Physical sciences, Radiation, Interference (wave propagation), 01 natural sciences, Asymmetry, Standard Model, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Pair production, 0103 physical sciences, Invariant mass, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, media_common
Abstract

Data on muon pair production obtained by the OPAL collaboration at centre of mass energies near the Z peak are analysed. Small angular mismatches between the directions of the two muons are used to assess the effects of initial state photon radiation and initial-final-state radiation interference on the forward-backward asymmetry of muon pairs. The dependence of the asymmetry on the invariant mass of the pair is measured in a model-independent way. Effective vector and axial-vector couplings of the Z boson are determined and compared to the Standard Model expectations., 31 pages, 8 figures, Accepted by Physics Letters B

Published
2001
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5. Measurement of the B0 lifetime and oscillation frequency using →ℓ decays

Author

G. Abbiendi, K. Ackerstaff, C. Ainsley, P.F. Åkesson, 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, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, G. Benelli, S. Bentvelsen, S. Bethke, O. Biebel, I.J. Bloodworth, O. Boeriu, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, P.E.L. Clarke, E. Clay, I. Cohen, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, A. Csilling, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. de Roeck, E. de Wolf, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D. Glenzinski, J. Goldberg, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, M. Harin-Dirac, A. Hauke, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, J.C. Hill, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, 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, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, W. Menges, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, M. Przybycień, A. Quadt, C. Rembser, P. Renkel, H. Rick, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, L. Stumpf, B. Surrow, S.D. Talbot, S. Tarem, R.J. Taylor, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence, S. Towers, D. Toya, T. Trefzger, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, B. Vachon, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, 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, Meson, 010308 nuclear & particles physics, Oscillation, 0103 physical sciences, Detector, 010306 general physics, 01 natural sciences
Abstract

The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results t_B0 = 1.541 +- 0.028 +- 0.023 ps, Dm_d = 0.497 +- 0.024 +- 0.025 ps-1 were obtained, where in each case the first error is statistical and the second systematic.

Published
2000

6. First measurement of the inclusive branching ratio of b hadrons to φ mesons in Z decays

Author

G. Abbiendi, K. Ackerstaff, C. Ainsley, 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, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, O. Biebel, 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, 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, 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, M. Fanti, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D. Glenzinski, J. Goldberg, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, 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, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, T. Kobayashi, M. Kobel, T.P. Kokott, 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, 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. Oh, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. 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, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, S. Schmitt, 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, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, 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, Meson, Branching fraction, High Energy Physics::Phenomenology, Hadron, Detector, High Energy Physics::Experiment, Nuclear Experiment, Production rate
Abstract

The inclusive production rate of phi mesons from the decay of b hadrons produced in Z0 decays was measured to be Br(b->phi+X) = 0.0282+-0.0013(stat.)+-0.0019(syst.), using data collected by the OPAL detector at LEP.

Published
2000

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. Measurement of the charm structure function <tex>F_{2,c}$</tex> of the photon at LEP

Author

G Abbiendi, C Ainsley, P.F Åkesson, G Alexander, J Allison, P Amaral, G Anagnostou, K.J Anderson, S Arcelli, S Asai, D Axen, G Azuelos, I Bailey, E Barberio, R.J Barlow, R.J Batley, P Bechtle, T Behnke, K.W Bell, P.J Bell, G Bella, A Bellerive, G Benelli, S Bethke, O Biebel, I.J Bloodworth, O Boeriu, P Bock, D Bonacorsi, M Boutemeur, S Braibant, L Brigliadori, R.M Brown, K Buesser, H.J Burckhart, J Cammin, S Campana, R.K Carnegie, B Caron, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, I Cohen, A Csilling, M Cuffiani, S Dado, G.M Dallavalle, S Dallison, A De Roeck, E.A De Wolf, K Desch, M Donkers, J Dubbert, E Duchovni, G Duckeck, I.P Duerdoth, E Elfgren, E Etzion, F Fabbri, L Feld, P Ferrari, F Fiedler, I Fleck, M Ford, A Frey, A Fürtjes, P Gagnon, J.W Gary, G Gaycken, C Geich-Gimbel, G Giacomelli, P Giacomelli, M Giunta, J Goldberg, E Gross, J Grunhaus, M Gruwé, P.O Günther, A Gupta, C Hajdu, M Hamann, G.G Hanson, K Harder, A Harel, M Harin-Dirac, M Hauschild, J Hauschildt, C.M Hawkes, R Hawkings, R.J Hemingway, C Hensel, G Herten, R.D Heuer, J.C Hill, K Hoffman, R.J Homer, D Horváth, R Howard, P Hüntemeyer, P Igo-Kemenes, K Ishii, H Jeremie, P Jovanovic, T.R Junk, N Kanaya, J Kanzaki, G Karapetian, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, R.K Keeler, R.G Kellogg, B.W Kennedy, D.H Kim, K Klein, A Klier, S Kluth, T Kobayashi, M Kobel, T.P Kokott, S Komamiya, L Kormos, R.V Kowalewski, T Krämer, T Kress, P Krieger, J von Krogh, D Krop, M Kupper, P Kyberd, G.D Lafferty, H Landsman, D Lanske, J.G Layter, A Leins, D Lellouch, J Letts, L Levinson, J Lillich, S.L Lloyd, F.K Loebinger, J Lu, J Ludwig, A Macpherson, W Mader, S Marcellini, T.E Marchant, A.J Martin, J.P Martin, G Masetti, T Mashimo, P Mättig, W.J McDonald, J McKenna, T.J McMahon, R.A McPherson, F Meijers, P Mendez-Lorenzo, W Menges, F.S Merritt, H Mes, A Michelini, S Mihara, G Mikenberg, D.J Miller, S Moed, W Mohr, T Mori, A Mutter, K Nagai, I Nakamura, H.A Neal, R Nisius, S.W O'Neale, A Oh, A Okpara, M.J Oreglia, S Orito, C Pahl, G Pásztor, J.R Pater, G.N Patrick, J.E Pilcher, J Pinfold, D.E Plane, B Poli, J Polok, O Pooth, M Przybycień, A Quadt, K Rabbertz, C Rembser, P Renkel, H Rick, J.M Roney, S Rosati, Y Rozen, K Runge, D.R Rust, K Sachs, T Saeki, O Sahr, E.K.G Sarkisyan, A.D Schaile, O Schaile, P Scharff-Hansen, J Schieck, T Schoerner-Sadenius, M Schröder, M Schumacher, C Schwick, W.G Scott, R Seuster, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G Siroli, A Skuja, A.M Smith, R Sobie, S Söldner-Rembold, S Spagnolo, F Spano, A Stahl, K Stephens, D Strom, R Ströhmer, S Tarem, M Tasevsky, R.J Taylor, R Teuscher, M.A Thomson, E Torrence, D Toya, P Tran, T Trefzger, A Tricoli, I Trigger, Z Trócsányi, E Tsur, M.F Turner-Watson, I Ueda, B Ujvári, B Vachon, C.F Vollmer, P Vannerem, M Verzocchi, H Voss, J Vossebeld, D Waller, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, T Wengler, N Wermes, D Wetterling, G.W Wilson, J.A Wilson, G Wolf, T.R Wyatt, S Yamashita, V Zacek, D Zer-Zion, L Zivkovic, and OPAL Collaboration

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, Meson, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, FOS: Physical sciences, Sigma, Perturbative QCD, 01 natural sciences, Charged particle, High Energy Physics - Experiment, Charm quark, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, High Energy Physics::Experiment, Charm (quantum number), 010306 general physics, Particle Physics - Experiment
Abstract

The production of charm quarks is studied in deep-inelastic electron-photon scattering using data recorded by the OPAL detector at LEP at normal e+e- centre-of-mass energies from 183 to 209 GeV. The charm quarks have been identified by full reconstruction of charged D* mesons using their decays into D0pi with the D0 observed in two decay modes with charged particle final states, Kpi and K3pi. The cross-section sigma(D*) for production of charged D* in the reaction e+e- -> e+e-D*X is measured in a restricted kinematical region using two bins in Bjorken x, 0.0014 < x < 0.1 and 0.1 < x < 0.87. From sigma(D*) the charm production cross-section sigma(e+e- -> e+e- ccbar X) and the charm structure function of the photon F 2,c are determined in the region 0.0014 < x < 0.87 and 5 < Q2 < 100 GeV2. For x > 0.1 the perturbative QCD calculation at next-to-leading order agrees perfectly with the measured cross-section. For x < 0.1 the measured cross-section is 43.8 +- 14.3 +- 6.3 +- 2.8 pb with a next-to-leading order prediction of 17.0+2.9-2.3 p.b, 18 pages, 4 figures

Published
2002

18. Genuine Correlations of Like-Sign Particles in Hadronic Z0 Decays

Author

G Abbiendi, C Ainsley, P.F Åkesson, G Alexander, J Allison, G Anagnostou, K.J Anderson, S Arcelli, S Asai, D Axen, G Azuelos, I Bailey, E Barberio, R.J Barlow, R.J Batley, T Behnke, K.W Bell, P.J Bell, G Bella, A Bellerive, G Benelli, S Bethke, O Biebel, I.J Bloodworth, O Boeriu, P Bock, J Böhme, D Bonacorsi, M Boutemeur, S Braibant, L Brigliadori, R.M Brown, H.J Burckhart, J Cammin, R.K Carnegie, B Caron, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, P.E.L Clarke, E Clay, I Cohen, J Couchman, A Csilling, M Cuffiani, S Dado, G.M Dallavalle, S Dallison, A De Roeck, E.A De Wolf, P Dervan, K Desch, B Dienes, M.S Dixit, M Donkers, J Dubbert, E Duchovni, G Duckeck, I.P Duerdoth, E Etzion, F Fabbri, L Feld, P Ferrari, F Fiedler, I Fleck, M Ford, A Frey, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, G Gaycken, C Geich-Gimbel, G Giacomelli, P Giacomelli, D Glenzinski, J Goldberg, K Graham, E Gross, J Grunhaus, M Gruwé, P.O Günther, A Gupta, C Hajdu, M Hamann, G.G Hanson, K Harder, A Harel, M Harin-Dirac, M Hauschild, J Hauschildt, C.M Hawkes, R Hawkings, R.J Hemingway, C Hensel, G Herten, R.D Heuer, J.C Hill, K Hoffman, R.J Homer, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, P Igo-Kemenes, K Ishii, A Jawahery, H Jeremie, C.R Jones, P Jovanovic, T.R Junk, N Kanaya, J Kanzaki, G Karapetian, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, R.K Keeler, R.G Kellogg, B.W Kennedy, D.H Kim, K Klein, A Klier, S Kluth, T Kobayashi, M Kobel, T.P Kokott, S Komamiya, R.V Kowalewski, T Krämer, T Kress, P Krieger, J von Krogh, D Krop, T Kuhl, M Kupper, P Kyberd, G.D Lafferty, H Landsman, D Lanske, I Lawson, J.G Layter, A Leins, D Lellouch, J Letts, L Levinson, J Lillich, C Littlewood, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Lu, J Ludwig, A Macchiolo, A Macpherson, W Mader, S Marcellini, T.E Marchant, A.J Martin, J.P Martin, G Martinez, G Masetti, T Mashimo, P Mättig, W.J McDonald, J McKenna, T.J McMahon, R.A McPherson, F Meijers, P Mendez-Lorenzo, W Menges, F.S Merritt, H Mes, A Michelini, S Mihara, G Mikenberg, D.J Miller, S Moed, W Mohr, T Mori, A Mutter, K Nagai, I Nakamura, H.A Neal, R Nisius, S.W O'Neale, A Oh, A Okpara, M.J Oreglia, S Orito, C Pahl, G Pásztor, J.R Pater, G.N Patrick, J.E Pilcher, J Pinfold, D.E Plane, B Poli, J Polok, O Pooth, A Quadt, K Rabbertz, C Rembser, P Renkel, H Rick, N Rodning, J.M Roney, S Rosati, K Roscoe, Y Rozen, K Runge, D.R Rust, K Sachs, T Saeki, O Sahr, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, P Scharff-Hansen, M Schröder, M Schumacher, C Schwick, W.G Scott, R Seuster, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, S Spagnolo, F Spano, M Sproston, A Stahl, K Stephens, D Strom, R Ströhmer, L Stumpf, B Surrow, S Tarem, M Tasevsky, R.J Taylor, R Teuscher, J Thomas, M.A Thomson, E Torrence, D Toya, T Trefzger, A Tricoli, I Trigger, Z Trócsányi, E Tsur, M.F Turner-Watson, I Ueda, B Ujvári, B Vachon, C.F Vollmer, P Vannerem, M Verzocchi, H Voss, J Vossebeld, D Waller, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, T Wengler, N Wermes, D Wetterling, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, V Zacek, D Zer-Zion, G., Abbiendi, C., Ainsley, P. F., Akesson, G., Alexander, J., Allison, G., Anagnostou, K. J., Anderson, S., Arcelli, S., Asai, D., Axen, G., Azuelo, I., Bailey, E., Barberio, R. J., Barlow, R. J., Batley, T., Behnke, K. W., Bell, P. J., Bell, G., Bella, A., Bellerive, G., Benelli, S., Bethke, O., Biebel, I. J., Bloodworth, O., Boeriu, P., Bock, J., Bohme, D., Bonacorsi, M., Boutemeur, S., Braibant, L., Brigliadori, R. M., Brown, H. J., Burckhart, J., Cammin, R. K., Carnegie, B., Caron, A. A., Carter, J. R., Carter, C. Y., Chang, D. G., Charlton, P. E., L., E., Clay, I., Cohen, J., Couchman, A., Csilling, M., Cuffiani, S., Dado, G. M., Dallavalle, S., Dallison, A., De Roeck, E. A., De, P., Dervan, K., Desch, B., Diene, M. S., Dixit, M., Donker, J., Dubbert, E., Duchovni, G., Duckeck, I. P., Duerdoth, E., Etzion, F., Fabbri, L., Feld, P., Ferrari, F., Fiedler, I., Fleck, M., Ford, A., Frey, A., Furtje, D. I., Futyan, P., Gagnon, J. W., Gary, G., Gaycken, C., Geich Gimbel, G., Giacomelli, P., Giacomelli, D., Glenzinski, J., Goldberg, K., Graham, E., Gro, J., Grunhau, M., Gruwe, P. O., Gunther, A., Gupta, C., Hajdu, M., Hamann, G. G., Hanson, K., Harder, A., Harel, M., Harin Dirac, M., Hauschild, J., Hauschildt, C. M., Hawke, R., Hawking, R. J., Hemingway, C., Hensel, G., Herten, R. D., Heuer, J. C., Hill, K., Hoffman, R. J., Homer, D., Horvath, K. R., Hossain, R., Howard, P., Huntemeyer, P., Igo Kemene, K., Ishii, A., Jawahery, H., Jeremie, C. R., Jone, P., Jovanovic, T. R., Junk, N., Kanaya, J., Kanzaki, G., Karapetian, D., Karlen, V., Kartvelishvili, K., Kawagoe, T., Kawamoto, R. K., Keeler, R. G., Kellogg, B. W., Kennedy, D. H., Kim, K., Klein, A., Klier, S., Kluth, T., Kobayashi, M., Kobel, T. P., Kokott, S., Komamiya, R. V., Kowalewski, T., Kramer, T., Kre, P., Krieger, J., von Krogh, D., Krop, T., Kuhl, M., Kupper, P., Kyberd, G. D., Lafferty, H., Landsman, D., Lanske, I., Lawson, J. G., Layter, A., Lein, D., Lellouch, J., Lett, L., Levinson, J., Lillich, C., Littlewood, S. L., Lloyd, F. K., Loebinger, G. D., Long, M. J., Losty, J., Lu, J., Ludwig, A., Macchiolo, A., Macpherson, W., Mader, S., Marcellini, T. E., Marchant, A. J., Martin, J. P., Martin, G., Martinez, G., Masetti, T., Mashimo, P., Mattig, W. J., Mcdonald, J., Mckenna, T. J., Mcmahon, R. A., Mcpherson, F., Meijer, P., Mendez Lorenzo, W., Menge, F. S., Merritt, H., Me, A., Michelini, S., Mihara, G., Mikenberg, D. J., Miller, S., Moed, W., Mohr, T., Mori, A., Mutter, K., Nagai, I., Nakamura, H. A., Neal, R., Nisiu, S. W., O'Neale, A., Oh, A., Okpara, M. J., Oreglia, S., Orito, C., Pahl, G., Pasztor, J. R., Pater, G. N., Patrick, J. E., Pilcher, J., Pinfold, D. E., Plane, B., Poli, J., Polok, O., Pooth, A., Quadt, K., Rabbertz, C., Rembser, P., Renkel, H., Rick, N., Rodning, J. M., Roney, S., Rosati, K., Roscoe, Y., Rozen, K., Runge, D. R., Rust, K., Sach, T., Saeki, O., Sahr, E. K., G., C., Sbarra, A. D., Schaile, O., Schaile, P., Scharff Hansen, M., Schroder, M., Schumacher, C., Schwick, W. G., Scott, R., Seuster, T. G., Shear, B. C., Shen, C. H., Shepherd Themistocleou, P., Sherwood, A., Skuja, A. M., Smith, G. A., Snow, R., Sobie, S., Soldner Rembold, Spagnolo, Stefania Antonia, F., Spano, M., Sproston, A., Stahl, K., Stephen, D., Strom, R., Strohmer, L., Stumpf, B., Surrow, S., Tarem, M., Tasevsky, R. J., Taylor, R., Teuscher, J., Thoma, M. A., Thomson, E., Torrence, D., Toya, T., Trefzger, A., Tricoli, I., Trigger, Z., Trocsanyi, E., Tsur, M. F., Turner Watson, I., Ueda, B., Ujvari, B., Vachon, C. F., Vollmer, P., Vannerem, M., Verzocchi, H., Vo, J., Vossebeld, D., Waller, C. P., Ward, D. R., Ward, P. M., Watkin, A. T., Watson, N. K., Watson, P. S., Well, T., Wengler, N., Werme, D., Wetterling, G. W., Wilson, J. A., Wilson, T. R., Wyatt, S., Yamashita, V., Zacek, D., Zer Zion, and OPAL Collaboration

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Monte Carlo method, Hadron, FOS: Physical sciences, Charge (physics), 01 natural sciences, Measure (mathematics), Electric charge, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Phase space, 0103 physical sciences, Rapidity, 010306 general physics, Cumulant, Particle Physics - Experiment
Abstract

Correlations among hadrons with the same electric charge produced in Z0 decays are studied using the high statistics data collected from 1991 through 1995 with the OPAL detector at LEP. Normalized factorial cumulants up to fourth order are used to measure genuine particle correlations as a function of the size of phase space domains in rapidity, azimuthal angle and transverse momentum. Both all-charge and like-sign particle combinations show strong positive genuine correlations. One-dimensional cumulants initially increase rapidly with decreasing size of the phase space cells but saturate quickly. In contrast, cumulants in two- and three-dimensional domains continue to increase. The strong rise of the cumulants for all-charge multiplets is increasingly driven by that of like-sign multiplets. This points to the likely influence of Bose-Einstein correlations. Some of the recently proposed algorithms to simulate Bose-Einstein effects, implemented in the Monte Carlo model PYTHIA, are found to reproduce reasonably well the measured second- and higher-order correlations between particles with the same charge as well as those in all-charge particle multiplets., 26 pages, 6 figures, Submitted to Phys. Lett. B

Published
2001

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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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25. 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

26. 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

27. 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

28. 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

29. Partial-wave analysis of the reaction K−p → Λ (1815) π between threshold and 2170 MeV

Author

P.J. Litchfield, Paul Baillon, H. Albrecht, E. Burkhardt, and R.J. Hemingway

Subjects
Physics, Nuclear and High Energy Physics, Amplitude, Partial wave analysis, Resonance, Atomic physics
Abstract

The reaction K−p → Λ(1815)π0 → K−pπ0 is found to be dominated by the formation of the 7 2 + ∑(2030) with an amplitude at resonance of 0.18 ± 0.04.

Published
1974

30. Production and decay of Ξ∗ (1820) in K−p reactions at 4.2 GeV/c

Author

J.B. Gay, R. Armenteros, J.P. Berge, Ph. Gavillet, R.J. Hemingway, R. Blokzijl, G.G.G. Massaro, H. Voorthuis, P.M. Heinen, W.J. Metzger, D.J. Schotanus, H.G. Tiecke, J.J.M. Timmermans, and R.T. Van de Walle

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Production (computer science), Channel (broadcasting), Sample (graphics), K channels
Abstract

Using a high statistics sample of K−p interactions at 4.2 GeV/c, the production and decay properties of the Ξ∗(1820) are discussed. The mass and width are found to be M = (1823 ± 2) MeV and Γ = (21 ± 7) MeV. Evidence is found for Ξ∗(2030) in the Σ K channel and for a new Ξ∗ at a mass of 2120 MeV in the ΛK− channel.

Published
1976

31. Triple-Regge analysis of the fragmentation processes $$p\underrightarrow K^ - \Sigma ^ + $$ and $$K^ - \underrightarrow P \Sigma ^ + $$ at 4.2 GeV/cat 4.2 GeV/c

Author

E. W. Kittel, Ch. de la Vaissiere, R. Blokzijl, W. D. Shephard, R.J. Hemingway, P. R. Lamb, G.F. Wolters, W. J. Metzger, P. Grossman, S. N. Ganguli, and J.C. Kluyver

Subjects
Physics, Particle physics, Fragmentation (mass spectrometry), Sigma, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment
Abstract

The inclusive production of Σ+ in K−p interactions at 4.2 GeV/c has been studied. Both the target fragmentation of the proton into Σ+ and the beam fragmentation of the kaon into Σ+ have been analysed with a triple-Regge model. In the\(p\bar \Sigma ^ + \) channel an effective exchange trajectory has been obtained which lies between the K and K(890) trajectories. For the\(K^ - \bar \Sigma ^ + \) channel a trajectory is found which may be interpreted as a Δ trajectory lowered by one-half.

Published
1977

32. The reactions K−p→π∓Σ±(1385) at 4.2 GeV/c

Author

J.C. Kluyver, G. G.G. Massaro, S-O. Holmgren, R.J. Hemingway, Fernando Barreiro, J. Zatz, Manuel Aguilar-Benitez, M.J. Losty, E.W. Kittel, R. T. Van de Walle, and R.P. Worden

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Amplitude, Quark model, Bubble chamber, Parity (physics), Exotic meson, Spin density, Quantum number, Helicity
Abstract

The reactions K−p→π−Σ+(1385) and K−p→π+Σ−(1385) are studied at 4.2 GeVc incident momentum using data from a high statistics bubble chamber experiment corresponding to ∼80 events/μb. The total and differential cross sections are presented. Amplitude analyses are performed and the complete Σ±(1385) helicity spin density matrices are extracted. The results are compared with the predictions of the additive quark model and exchange degeneracy. A substantial cross section is observed for the reaction K−p→π+Σ−(1385) in the forward direction, which implies exotic meson quantum numbers in the t-channel. One possible interpretation of this process provides an explanation for the small but significant violations of the additive quark model predictions observed in the reaction K−p→π−Σ+(1385) at low four-momentum transfer. In the backward direction unnatural parity exchange is shown to give a larger contribution to K−p→Σ−(1385)π+ than natural parity exchange.

Published
1977

33. Production of Λ(1405) in K−p reactions at 4.2 GeV/c

Author

R.J. Hemingway

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Large Hadron Collider, Parity (physics), Hydrogen bubble
Abstract

From a 130 event/μb exposure of the CERN 2 m hydrogen bubble chamber to a 4.2 GeV/c K− beam, a high statistics sample of Λ(1405) in a production reaction has been isolated. The reaction K−p→Σ+(1660)π−, Σ+(1660)→Λ(1405)π+, Λ(1405)→Σπ has enabled an almost pure selection of Λ(1405) events. A Byers-Fenster spin-parity analysis is in agreement with the J = 1 2 assignment but gives no parity discrimination. The measured line-shape of the Λ(1405) is particularly useful in allowing a better understanding of the nature of this resonance.

Published
1985

34. A study of non-charge-exchange production in the reaction at 4.2 GeV/c

Author

H.G.J.M. Tiecke, G. G.G. Massaro, S. Yamashita, H. Voorthuis, S-O. Holmgren, L. McDowell, Louis Lyons, R.J. Hemingway, B. Jongejans, J.J. Engelen, E.W. Kittel, Joris S. M. Vergeest, P. Grossmann, M.J. Losty, and M.J. Holwerda

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Amplitude, Parity (physics), Charge exchange
Abstract

The Kπ− system produced in the reaction Kp → K0π−p at 4.2 GeV/c is studied using high-statistics bubble-chamber data. The spin-parity structure is analysed as a function of the K0π− mass up to 1.52 GeV. Production of K∗(890) and K∗(1420) is observed in helicity-0 and helicity-1 states. Contributions of natural and unnatural parity exchange are present. Considerable S-wave production is observed over the whole mass region considered. We also study the t′ dependence of the K∗(890) and K∗(1420) amplitudes. A comparison of our results on K∗(890) production with the results of an analysis of charge-exchange K∗(890) production, allows the separation of I = 0 and I = 1 exchange amplitudes. Some qualitative remarks are made concerning K∗(1420) production.

Published
1978

35. Production and decay properties of the δ (970) meson

Author

J.B. Gay, V. Chaloupka, Ph. Gavillet, R.J. Hemingway, F. Marzano, L. Montanet, R. Blokzijl, B. Jongejans, G.G.G. Massaro, P.M. Heinen, W.J. Metzger, and J.J.M. Timmermans

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Meson, Production (computer science), Particle Physics
Abstract

Using an 880 events per microbarn sample of K − p interactions at 4.2 GeV/ c the production and decay properties of the δ (970) have been investigated in the following reactions: K − p → Σ + (1385) ηπ − and K − p ar Σ + (1385)K 0 K − .

Published
1976

36. Partial-wave analysis of the low-mass (π+π−p) system produced in K−p interactions at 4.2 GeV/c

Author

B. Jongejans, S-O. Holmgren, P.M. Heinen, E.W. Kittel, M.J. Losty, Marcos Cerrada, W. J. Metzger, H. Voorthuis, R. T. Van de Walle, M.M. Schouten, J.J. Engelen, Joris S. M. Vergeest, and R.J. Hemingway

Subjects
Physics, Momentum, Nuclear physics, Nuclear and High Energy Physics, Partial wave analysis, Atomic physics, Low Mass, P system
Abstract

A partial-wave analysis of the low-mass (π+π−p) system produced in the reaction K−p → K−(π+π−p) at 4.2 GeV/c incident momentum is performed in order to study the two (π+π−p) enhancements around 1500 and 1700 MeV. It is found that the low-mass (π+π−p) system can be described using the spin-parity states J P = 1 2 + , 3 2 − and 5 2 + only. In the 1500 MeV region contributions are observed from the 1 2 + wave decaying into pϵ and the 3 2 − wave decaying into Δ++π−; in the 1700 MeV region contributions are found from the 1 2 + wave decaying into Δ++π−, the 3 2 − wave decaying into pϵ, and the 5 2 + wave decaying into pϵ.

Published
1977

37. Partial-wave analysis of the reaction K−p → Λ (1520) π in the energy region 1915 – 2170 MeV

Author

P.J. Litchfield, R.J. Hemingway, H. Schleich, A. Putzer, and Paul Baillon

Subjects
Physics, Nuclear and High Energy Physics, Amplitude, Partial wave analysis, Resonance, Atomic physics, Energy (signal processing)
Abstract

A partial-wave analysis has been carried out on the reaction K− p → Λ (1520)π → K−pπ0. The ∑ (2030) is observed with an amplitude at resonance of 0.14 ± 0.03. Evidence is also presented for the formation of the 3 − 2 ∑(1940) .

Published
1974

38. Study of hypercharge exchange reactions of the type at 4.2 GeV/c

Author

G. G.G. Massaro, R.J. Hemingway, H.G. Tiecke, M.J. Losty, D. Z. Toet, Joris S. M. Vergeest, G.F. Wolters, J. Zatz, Manuel Aguilar-Benitez, R. T. Van de Walle, J.J. Engelen, R.P. Worden, Fernando Barreiro, S-O. Holmgren, and J.C. Kluyver

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Hypercharge, Meson, High Energy Physics::Phenomenology, Momentum transfer, Quark model, Hyperon, Duality (optimization), Resonance (particle physics), Nuclear physics, Bubble chamber, Nuclear Experiment
Abstract

Results are presented for the quasi two-body hypercharge exchange reactions of the type using data from a high statistics bubble chamber experiment. Total and differential cross sections and the momentum transfer dependence of the meson and hyperon resonance single density matrix elements are discussed. Amplitude analyses are performed for the first two reactions. The results are compared with quark model and duality predictions and with those from other related reactions.

Published
1977

40. A measurement of the η′ spin parity

Author

P. F. Loverre, S-O. Holmgren, Marcos Cerrada, B. Foster, F. Marzano, R. Blokzijl, J. Timmermans, H.G.J.M. Tiecke, G. G.G. Massaro, V. Chaloupka, F. Wagner, B. Jongejans, R.J. Hemingway, M.J. Losty, W.L. McDowell, and D. J. Schotanus

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Statistical sensitivity, Bubble chamber, Parity (physics)
Abstract

The spin parity of the η′ (958) is studied in the reaction K − p → η ' Λ at 4.2 GeV/ c , using bubble chamber data with a statistical sensitivity of 128 events/μb. The data unambiguously prefer the 0 − assignment.

Published
1977

41. Study of Σ±(1385) inclusive production in K−p interactions at 4.2 GeV/c

Author

R. Blokzijl, J.P. Berge, J.C. Kluyver, G.F. Wolters, Ph. Gavillet, E.W. Kittel, Fernando Barreiro, W. D. Shephard, S. N. Ganguli, J.J. Engelen, and R.J. Hemingway

Subjects
Quark, Nuclear physics, Physics, Density matrix, Nuclear and High Energy Physics, Recoil, Fragmentation (mass spectrometry), Quark model, Momentum transfer
Abstract

Properties of Σ ± (1385) inclusively produced in 4.2 GeV/ c K − p interactions are studied. Inclusive cross sections are presented together with differential cross sections as functions of x and p t 2 for both Σ + (1385) and Σ − (1385). The complete density matrix for Σ + (1385) production at small momentum transfer is studied as a function of t and of recoil mass MM 2 . Substantial agreement with the predictions of the additive quark model is found. The Σ + (1385) production in the target fragmentation region is studied in the framework of the triple-Regge model.

Published
1977

42. Backward production of the B meson in K−p interactions at

Author

M. Zralek, M. Mazzucato, Ph. Gavillet, B. Foster, Jon-Paul R. Wells, J.C. Kluyver, J-C. Marin, Atul Gurtu, L. Montanet, B. Jongejans, J.J. Engelen, C. Dionisi, P. Grossmann, R.J. Hemingway, Joris S. M. Vergeest, R. Blokzijl, G. G.G. Massaro, E. Pagiola, and M.J. Losty

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, Momentum, Nuclear physics, Mass enhancement, Baryon, High Energy Physics::Experiment, B meson, Production (computer science), Nuclear Experiment, Pseudovector
Abstract

The backward production of the B(1235) meson is studied in the reaction K−p→Σ−π+ω. This reaction is observed in the final state Σ−π+π+π−π0. A π+ω mass enhancement is visible in the region of the B meson for events with small |u|K− →Σ−) squared four-momentum transfer. The properties of the enhancement agree with those of the B meson. The cross section for K−p→Σ−B+ at 4.15 GeV c incident K− momentum is (3.2 ± 0.5) μb. The backward production of the B meson is compared with similar baryon exchange productions of the A1 and C(Q1) axial vector mesons observed in the same experiment.

Published
1978

43. The reactions K− + p → pseudoscalar meson + Λ (1520) at 4.2 GeV/c

Author

G. G.G. Massaro, M.J. Losty, D. J. Schotanus, W. J. Metzger, Jon-Paul R. Wells, S-O. Holmgren, J. Timmermans, J.C. Kluyver, R.J. Hemingway, B. Jongejans, Manuel Aguilar-Benitez, S. Barlag, R. Blokzijl, B. Foster, and P. Grossmann

Subjects
Baryon, Nuclear physics, Physics, Nuclear and High Energy Physics, Matrix (mathematics), Particle physics, Spin density, Pseudoscalar meson
Abstract

The total and differential cross sections of the reactions K−p → π0Λ (1520), ηΛ(1520) and η′ Λ(1520) have been measured. Prominent forward peaks are onserved in all three reactions. The first reaction shows also a backward peak. The spin density matrix elements of the Λ(1520) in this reaction are determined. For forward production the results show a remarkable alignment of the Λ(1520) corresponding to an M2 transition in the model of Stodolsky-Sakurai for 32− baryon production.

Published
1979

44. New particle searches and discoveries

Author

M.J. Losty, R.J. Hemingway, Naomi Barash-Schmidt, Vladimir Chaloupka, Robert L. Kelly, Arthur Hinton Rosenfeld, Angela Barbaro-Galtieri, Thomas G. Trippe, Matts Roos, Alan Rittenberg, Charles P. Horne, George P. Yost, C. Bricman, and B. Armstrong

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle properties, Bearing (mechanical), law, High Energy Physics::Phenomenology, Particle, High Energy Physics::Experiment, Particle Data Group, Lepton, law.invention
Abstract

This supplement to the 1976 edition of “Review of particle properties”, Particle Data Group [Rev. Mod. Phys. 48, No. 2, Part II (1976)], contains tabulations of experimental data bearing on the “new particles” and related topics; categories covered include charmed particles, ψ's and their decay products, and heavy leptons. Errata to the previous edition are also given.

Published
1977

45. Production of Σ(1660) in K−p interactions at 4.2 GeV/c

Author

J.J.M. Timmermans, J.J. Engelen, P.M. Heinen, W.J. Metzger, R.T. Van De Walle, J.P. Berge, Ph. Gavillet, J.B. Gay, R.J. Hemingway, R. Blokzijl, A.J. De Groot, G.G.G. Massaro, and P.R. Lamb

Subjects
Physics, Nuclear and High Energy Physics, Resonance, Atomic physics, Multiplet
Abstract

The reaction of K−p → Σ+(1660)π− was studied in a 65 event/μb sample of Σππ(π), Λππ(π) and pK0π− final states. The main production features observed are that the Σ(1660) decaying into Σππ is mostly Λ(1405)π and is produced only at small t; the Σ(1660) decaying into Σπ shows both forward and backward production. This confirms earlier results suggesting the existence of two Σ(1660) resonances. An Adair analysis and a (model-dependent) moments analysis find a J = 32 preference for the Σ+ (1660)→ Λ(1405)π+ → Σ+π−π+; a Dalitz-Miller analysis of the decay Σ+(1660) → Λ(1405)π+ → Σ−π+π+ determines JP to be 32−. For the Σ+(1660) → Σ0π+ a moments analysis suggests J = 32. Branching ratios are determined, which (with the exceptation of the Λ(1405)π mode) are in reasonable agreement with results from formation experiments for the JP = 32− Σ(1660) resonance. We compare our branching ratios with SU(3) and SU(6) predictions; the latter comparison suggests that, unless there is strong configuration mixing, Σ(1660) → Λ(1405)π, if 32−, cannot be a member of the (70, 1−) multiplet.

Published
1976

46. Spin-parity structure of the system produced in the charge-exchange reaction at 4.2 GeVc

Author

J.S.M. Vergeest, M. Cerrada, V. Chaloupka, Ph. Gavillet, J.B. Gay, R.J. Hemingway, M.J. Losty, J.J. Engelen, E.W. Kittel, W.J. Metzger, H.G.J.M. Tiecke, B. Jongejans, H. Voorthuis, and G.F. Wolters

Subjects
Physics, Nuclear and High Energy Physics, Branching fraction, Partial wave analysis, S-wave, Parity (physics), Atomic physics, Polarization (waves), Charge exchange
Abstract

A partial wave analysis of the K 0 π + π − system produced in the charge exchange reaction K − p → ( K 0 π + π − ) n at 4.2 GeV/ c has been performed both as a function of Kππ mass and of t ′. The 1 + S wave forms the largest contribution to the K ππ system and peaks at roughly the same mass as the Q in diffractive K ππ production. The polarization properties of the 1 + S ( K ∗ π) and 1 + S (Kϱ) waves differ fromt those of the diffractive 1 + wave. There is some evidence for a resonance contribution to 1 + S ( K ∗ π) . The strong 2 + wave the K ∗ (1420) and the K ϱ/ K ∗ ϱ decay branching ratio determined to be 0.36±0.10. An enhancement with spin-parity 1 − is observed under K ∗ (1420) .

Published
1976

47. (2030) production in K−p reactions at 4.2 GeV/c

Author

R.J. Hemingway, R. Armenteros, J.P. Berge, J. Diaz, J.B. Gay, P. Trepagnier, B. Jongejans, G.G.G. Massaro, H. Voorthuis, P.M. Heinen, W.J. Metzger, H.G. Tiecke, J.J.M. Timmermans, P.R. Lamb, and W.L. McDowell

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Bubble chamber, Production (computer science), Channel (broadcasting), Atomic physics
Abstract

Significant production of (2030) is observed in the channel K − p → (Σ K − K + from a high statistics bubble chamber exposure at 4.2 GeV/ c . The mass and width are determined to be 2024 ± 2 MeV and 16 ± 5 MeV respectively. Apart from Σ K , the only other decay channel is found to be Λ K .

Published
1977

48. Lambda production in the fragmentation processes

Author

R. Blokzijl, A.J. De Groot, B. Jongejans, J.C. Kluyver, G.G.G. Massaro, G.F. Wolters, S. Nilsson, J.P. Berge, J.B. Gay, R.J. Hemingway, B. Marechal, P.M. Heinen, W. Kittel, W.J. Metzger, H.G. Tiecke, J.J.M. Timmermans, and R.T. Van De Walle

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Pion, Fragmentation (mass spectrometry), Meson, Nuclear Theory, High Energy Physics::Experiment, Residual mass, Atomic physics, Nuclear Experiment, Lambda, Nucleon
Abstract

In the reaction K − +p→ Λ +X at 4.25 GeV/ c both the target fragmentation of the proton into lambda and the beam fragmentation of kaon into lambda have been studied. The sample consists of 21 000 Λ events with t >−1.0 (GeV/ c ) 2 and 9000 Λ events with u > −1.0 (GeV/ c ) 2 . Abundant π 0 and meson resonance production for residual masses M x c 2 is observed. In the t -channel of am effective exchange trajectory is deduced. which lies between the K and K(890) trajectories. In the u -channel the effective exchange trajectory is in good agreement with a nucleon trajectory. The extrapolated average pion multiplicities of the residual mass system in the t -channel are in very good agreement with the values measured in antiproton-proton annihilations at rest.

Published
1975

49. Amplitude analysis for the process K− p → (π+ π−)s-wave ϵ0 (1385)

Author

Manuel Aguilar-Benitez, J. Timmermans, J.G. Kluyver, M.J. Losty, G. G.G. Massaro, R. T. Van de Walle, R.J. Hemingway, Fernando Barreiro, S-O. Holmgren, and K. Zalewski

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Matrix (mathematics), Amplitude, S-wave, Scalar (mathematics), Quark model, Vertex (curve), Duality (optimization), Spin density
Abstract

Transversity amplitudes and spin density matrix elements are determined for the process K− p → (π+ π−)s-wave ϵ0(1385). Predictions of the additive quark model and of duality diagrams are tested and found consistent with the data; this is the first information about the applicability of these models to processes where a scalar object is produced at the mesonic vertex.

Published
1977

50. An I = 1 enhancement at a mass of 1550 MeV in the (Λπ) and (Σπ)-systems

Author

C. Dionisi, R. Armenteros, J. Diaz, Ph. Gavillet, J.B. Gay, A. Gurtu, R.J. Hemingway, M. Mazzucato, P. Trepagnier, R. Blokzijl, G.G.G. Massaro, B. Jongejans, J. Engelen, J.J. Timmermans, R.T. Van De Walle, B. Foster, P.R. Lamb, and W.L. McDowell

Subjects
Nuclear physics, Momentum, Physics, Nuclear and High Energy Physics, Branching fraction
Abstract

Evidence is presented for an I = 1 enhancement observed in the reactions K−p→Λ(Σ)K01K±π∓ at 4.2 GeV c inciden momentum. The mass and width of the proposed new Y∗ are, respectively, (1553 ± 7) MeV) and (80 ± 30) MeV. A decay branching ratio Σπ (Σπ + Λπ) = (35 ± 12)% is also obtained.

Published
1978

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