Autor: |
Sachio Komamiya, A. T. Watson, M. Boutemeur, F. S. Merritt, F. Scharf, T. P. Kokott, J. Letts, T. Saeki, Satoshi Mihara, German Martinez, J. Bechtluft, J. A. McKenna, G. G. Hanson, P. Scharff-Hansen, R. Davis, Randall Sobie, G. D. Lafferty, K. Sachs, S. Betts, M. Hapke, M. Fanti, G. Giacomelli, M. J. Oreglia, I. Lawson, Shlomo Dado, J. R. Carter, G. N. Patrick, A. M. Smith, Dave Charlton, R. Bartoldus, A. De Roeck, W. R. Gibson, H. O. Ogren, Christoph Geich-Gimbel, N. Altekamp, H. Voss, Guenter Duckeck, J. M. Roney, Robert McPherson, J. Grunhaus, S. R. Lautenschlager, K. Stoll, Andris Skuja, D. M. Strom, Gregor Herten, K. Harder, R. J. Barlow, G. Gaycken, P. G. Bright-Thomas, R. D. Heuer, D. J. Miller, Fabrizio Fabbri, D. C. Imrie, Claire Shepherd-Themistocleous, M. Schumacher, S. Petzold, R. Bürgin, O. Runolfsson, R. M. Brown, Lorne Levinson, M. S. Dixit, Frans Meijers, Giora Mikenberg, S. F. Ashby, Koichi Nagai, J. Schieck, Tetsuro Mashimo, Achim Stahl, Vakhtang Kartvelishvili, Paul Kyberd, J. E. Conboy, A. Fürtjes, C. Y. Chang, Ehud Duchovni, W. Mohr, M. Jimack, G. P. Siroli, J. E. Pilcher, F. Odorici, R. Van Kooten, T. R. Junk, A. Biguzzi, A. A. Faust, W. Gorn, P. Taras, F. K. Loebinger, P. S. Wells, Claudio Grandi, J. S. White, Christoph Schwick, A. Michelini, J. Steuerer, J. G. Layter, A. W. Lloyd, Ekg Sarkisyan, R. J. Hemingway, C. Hartmann, S. B. Anderson, D. E. Plane, Terry Richard Wyatt, Gideon Bella, K. Stephens, Stephen Hillier, H. A. Neal, G. M. Dallavalle, Ivor Fleck, G. W. Wilson, Satoshi Tanaka, Joleen Pater, A. D. Schaile, Gabriella Pasztor, M. Hauschild, C. Markopoulos, P. Vannerem, M. A. Thomson, A. Macpherson, H. J. Burckhart, Jacqueline Batley, F. Wäckerle, C. Littlewood, B. W. Kennedy, James Pinfold, R. Perez-Ochoa, R. Seuster, P. Jovanovic, A. Klier, Austin Ball, D. M. Gingrich, T. Kobayashi, E. K. U. Gross, L. Brigliadori, V. Gibson, H. Mes, S. M. Gascon-Shotkin, Peter Krieger, J. Gascon, R. Howard, Stan Bentvelsen, M. Sproston, K. Roscoe, G. A. Snow, C. P. Ward, Alessandro Montanari, D. Lanske, M. F. Turner-Watson, I. Trigger, I. P. Duerdoth, S. Braibant, A. Macchiolo, Peter R Hobson, D. R. Rust, P. E.L. Clarke, Klaus Kurt Desch, E. Torrence, M. Kobel, S. Söldner-Rembold, D. R. Ward, T. Kress, C. M. Hawkes, R. Mir, J. P. Martin, E. Clay, Otmar Biebel, R. Kowalewski, V. Zacek, R. Hawkings, S. W. O'Neale, K. J. Anderson, D. Zer-Zion, O. C. Cooke, P. Hüntemeyer, S. Arcelli, A. M. Lee, P. I. Kayal, Georges Azuelos, P. Pfeifenschneider, T. Kuhl, John Allison, J. W. Gary, Raimund Ströhmer, Norbert Wermes, E. von Törne, Sherry Towers, T. Kawamoto, S. De Jong, E. Tsur, D. S. Koetke, Marcello Mannelli, Richard Teuscher, A. S. Turcot, C. R. Jones, S. Orito, J. Patt, Richard Nisius, A. M. Rossi, André Schöning, P. Poffenberger, M. Fierro, M. Verzocchi, K. W. Bell, H. Rick, O. Sahr, F. G. Oakham, B. List, Marco Cuffiani, F. Fiedler, J. Pálinkás, Kiyotomo Kawagoe, B. Schmitt, E. L. Barberio, Gideon Alexander, Paolo Giacomelli, M. Hansroul, Paolo Capiluppi, J. C. Hill, Beatrix Dienes, C. Burgard, R. J. Homer, R. G. Kellogg, R. L. Coxe, W. J. McDonald, B. C. Shen, A. Hocker, M. Kolrep, Siegfried Bethke, D. Liu, A. K. Honma, D. Chrisman, G. D. Long, K. R. Hossain, Stefano Marcellini, Volker Blobel, W. G. Scott, I. Nakamura, Stephen Lloyd, W. M. Sang, Claudia Ciocca, D. Glenzinski, Dezso Horvath, M. J. Losty, Jean-Arcady Meyer, Michael Hildreth, Alain Bellerive, N. L. Rodning, C. Sbarra, F. R. Jacob, Daniele Bonacorsi, J. Lauber, J. von Krogh, S. D. Talbot, M. Gruwé, L. A. del Pozo, T. J. McMahon, C. Couyoumtzelis, J. Dubbert, R. K. Carnegie, M. Herndon, D. Eatough, T. Behnke, M. Bobinski, J. A. Wilson, J. Böhme, D. Lazic, P. Gagnon, G. Yekutieli, M. Przybycień, A. A. Carter, Ron Folman, A. Sittler, Zoltan Laszlo Trocsanyi, Giovanni Abbiendi, S. D. Bird, D. Axen, A. Jawahery, Peter Sherwood, Stefan Schmitt, Alexander Wagner, J. Ludwig, K. Runge, P. Bock, Shoji Asai, P. G. Estabrooks, R. K. Keeler, Daniel Lellouch, N. K. Watson, Takehiko Mori, P. Mättig, P. M. Watkins, I. J. Bloodworth, S. Baumann, Yoram Rozen, E. A. Mckigney, J. Polok, D. Karlen, D. I. Futyan, J. Goldberg, B. Nellen, H. G. Evans, I. Cohen, Christoph Rembser, Erez Etzion, Stefan Kluth, Shlomit Tarem, B. Surrow, S. A. Robins, R. Liebisch, K. Ackerstaff, A. J. Martin, S. Yamashita, P. Igo-Kemenes, K. Ishii, H. Jeremie, W. Mader, O. Schaile, C. K. Hargrove, S. Robertson, Matthias Schröder, Sven Menke, M. Thiergen, Tara Shears |
Rok vydání: |
1999 |
Předmět: |
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Zdroj: |
The European Physical Journal C. 8:23-40 |
ISSN: |
1434-6052 1434-6044 |
DOI: |
10.1007/s100529901083 |
Popis: |
Photonic events with large missing energy have been observed in $\mathrm e^+e^-$ collisions at centre-of-mass energies of 130, 136 and 183 GeV collected in 1997 using the OPAL detector at LEP. Results are presented for event topologies with a single photon and missing transverse energy or with an acoplanar photon pair. Cross-section measurements are performed within the kinematic acceptance of each selection. These results are compared with the expectations from the Standard Model process ${\rm e}^+{\rm e}^-\to\nu\overline{\nu}$ + photon(s). No evidence is observed for new physics contributions to these final states. Using the data at $\sqrt{s}$ = 183 GeV, upper limits on ${\sigma({\rm e^+e^-}\to{\rm XY})\cdot{\rm BR}(\rm X \to Y \gamma)}$ and ${\sigma({\rm e^+e^-}\to{\rm XX})\cdot{\rm BR}^2(\rm X \to Y \gamma)}$ are derived for the case of stable and invisible Y. These limits apply to single and pair production of excited neutrinos ( $\rm X = \nu^*, Y = \nu$ ), to neutralino production ( $\rm X={{\tilde{\chi}}^{0}}_{2}, Y={{\tilde{\chi}}^{0}}_{1}$ ) and to supersymmetric models in which $\rm X = {{\tilde{\chi}}^{0}}_{1}$ and $\rm Y=\tilde{\mathrm{G}}$ is a light gravitino. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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