Measurements of the Strong Coupling Constant and the QCD Colour Factors using Four-jet Observables from Hadronic Z Decays

Data from e+e- annihilation into hadrons, taken with the ALEPH detector at the Z resonance, are analyzed. The four-jet rate is studied as a function of the resolution parameter and compared to next-to-leading order calculations combined with resummation of large logarithms. Angular correlations in f...

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Detalles Bibliográficos
Autores principales: Heister, A, Schael, S, Barate, R, De Bonis, I, Décamp, D, Goy, C, Lees, J P, Merle, E, Minard, M N, Pietrzyk, B, Boix, G, Bravo, S, Casado, M P, Chmeissani, M, Crespo, J M, Fernández, E, Fernández-Bosman, M, Garrido, L, Graugès-Pous, E, Martínez, M, Merino, G, Miquel, R, Mir, L M, Pacheco, A, Ruiz, H, Colaleo, A, Creanza, D, De Palma, M, Iaselli, Giuseppe, Maggi, G, Maggi, M, Nuzzo, S, Ranieri, A, Raso, G, Ruggieri, F, Selvaggi, G, Silvestris, L, Tempesta, P, Tricomi, A, Zito, G, Huang, X, Lin, J, Ouyang, Q, Wang, T, Xie, Y, Xu, R, Xue, S, Zhang, J, Zhang, L, Zhao, W, Abbaneo, D, Azzurri, P, Buchmüller, O L, Cattaneo, M, Cerutti, F, Clerbaux, B, Drevermann, H, Forty, R W, Frank, M, Gianotti, F, Greening, T C, Hansen, J B, Harvey, J, Hutchcroft, D E, Janot, P, Jost, B, Kado, M, Mato, P, Moutoussi, A, Ranjard, F, Rolandi, Luigi, Schlatter, W D, Schneider, O, Sguazzoni, G, Tejessy, W, Teubert, F, Valassi, Andrea, Videau, I, Ward, J, Badaud, F, Falvard, A, Gay, P, Henrard, P, Jousset, J, Michel, B, Monteil, S, Montret, J C, Pallin, D, Perret, P, Hansen, J D, Hansen, J R, Hansen, P H, Nilsson, B S, Kyriakis, A, Markou, C, Simopoulou, Errietta, Vayaki, Anna, Zachariadou, K, Blondel, A, Bonneaud, G R, Brient, J C, Rougé, A, Rumpf, M, Swynghedauw, M, Verderi, M, Videau, H L, Ciulli, V, Focardi, E, Parrini, G, Antonelli, A, Antonelli, M, Bencivenni, G, Bossi, F, Campana, P, Capon, G, Chiarella, V, Laurelli, P, Mannocchi, G, Murtas, F, Murtas, G P, Passalacqua, L, Pepé-Altarelli, M, Halley, A, Lynch, J G, Negus, P, O'Shea, V, Raine, C, Thompson, A S, Wasserbaech, S R, Cavanaugh, R J, Dhamotharan, S, Geweniger, C, Hanke, P, Hepp, V, Kluge, E E, Putzer, A, Stenzel, H, Tittel, K, Wunsch, M, Beuselinck, R, Binnie, David M, Cameron, W, Dornan, P J, Girone, M, Marinelli, N, Sedgbeer, J K, Thompson, J C, Ghete, V M, Girtler, P, Kneringer, E, Kuhn, D, Rudolph, G, Bouhova-Thacker, E, Bowdery, C K, Finch, A J, Foster, F, Hughes, G, Jones, R W L, Pearson, M R, Robertson, N A, Jakobs, K, Kleinknecht, K, Quast, G, Renk, B, Sander, H G, Wachsmuth, H W, Zeitnitz, C, Bonissent, A, Coyle, P, Leroy, O, Payre, P, Rousseau, D, Talby, M, Ragusa, F, David, A, Dietl, H, Ganis, G, Hüttmann, K, Lütjens, G, Männer, W, Moser, H G, Settles, Ronald, Wiedenmann, W, Wolf, G, Boucrot, J, Callot, O, Davier, M, Duflot, L, Grivaz, J F, Heusse, P, Jacholkowska, A, Lefrançois, J, Veillet, J J, Yuan, C, Bagliesi, G, Boccali, T, Foà, L, Giammanco, A, Giassi, A, Ligabue, F, Messineo, A, Palla, Fabrizio, Sanguinetti, G, Sciabà, A, Spagnolo, P, Tenchini, Roberto, Venturi, A, Verdini, P G, Xie, Z, Blair, G A, Cowan, G, Green, M G, Medcalf, T, Misiejuk, A, Strong, J A, Teixeira-Dias, P, Clifft, R W, Edgecock, T R, Norton, P R, Tomalin, I R, Bloch-Devaux, B, Colas, P, Emery, S, Kozanecki, Witold, Lançon, E, Lemaire, M C, Locci, E, Pérez, P, Rander, J, Renardy, J F, Roussarie, A, Schuller, J P, Schwindling, J, Trabelsi, A, Vallage, B, Konstantinidis, N P, Litke, A M, Taylor, G, Booth, C N, Cartwright, S L, Combley, F, Lehto, M H, Thompson, L F, Affholderbach, K, Böhrer, A, Brandt, S, Grupen, Claus, Ngac, A, Prange, G, Sieler, U, Giannini, G, Rothberg, J E, Armstrong, S R, Berkelman, K, Cranmer, K, Ferguson, D P S, Gao, Y, González, S, Hayes, O J, Hu, H, Jin, S, Kile, J, McNamara, P A, Nielsen, J, Pan, Y B, Von Wimmersperg-Töller, J H, Wu, J, Wu Sau Lan, Wu, X, Zobernig, G
Lenguaje:eng
Publicado: 2002
Materias:
Particle Physics - Experiment
Acceso en línea:https://dx.doi.org/10.1140/epjc/s2002-01114-2
http://cds.cern.ch/record/551536
Descripción
Sumario:Data from e+e- annihilation into hadrons, taken with the ALEPH detector at the Z resonance, are analyzed. The four-jet rate is studied as a function of the resolution parameter and compared to next-to-leading order calculations combined with resummation of large logarithms. Angular correlations in four-jet events are measured and compared to next-to-leading order QCD predictions. With these observables two different measurements are performed. In a first analysis the strong coupling constant is measured from the four-jet rate yielding alpha_s(M_ Z}) = 0.1170 \pm 0.0001(stat) \pm 0.0014(sys) In a second measurement the strong coupling constant and the \textsc{QCD} colour factors are determined simultaneously from a fit to the four-jet rate and the four-jet angular correlations, giving alpha_s(M_ Z) = 0.119 \pm 0.006(stat) \pm 0.026 (sys) C_A = 2.93 \pm 0.14(stat) \pm 0.58 (sys) C_F} = 1.35 \pm 0.07 (stat) \pm 0.26 (sys) in good agreement with the expectation from QCD.

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