Search for particles with unexpected mass and charge in Z decays

Buskilic, D.; Décamp, D.; Goy, C.; Lees, J. P.; Minard, M.-N.; Mours, B.; Pietrzyk, B.; Alemany, R.; Ariztizabal, F.; Comas, P.; Crespo, J.M.; Delfino, M.; Fernández, E.; Fernández-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T. S.; Pacheco, A.; Aranda, C. Padilla; Pascual, Á.; Creanza, D.; Palma, M. De; Farilla, A.; Iaselli, G.; Mäggi, G.; Maggi, M.; Natali, S.; Nuzzo, N.; Quattromini, M.; Ranieri, A.; Raso, G.; Romanò, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X. T.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bauerdick, L. A. T.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R.; Ganis, G.; Hagelberg, R.; Harvey, J.; Haywood, S. J.; Hilgart, J.; Jacobsen, R.G.; Jost, B.; Knobloch, J.; Lehraus, I.; Löhse, T.; Lusiani, A.; Martı́nez, M.; Mató, P.; Meinhard, H.; Mitten, A.; Miotto, A.; Miquel, R.; Moser, H. G.; Palazzi, P.; Perlas, J. A.; Pusztaszeri, J. F.; Ranjard, F.; Redlinger, G.; Rolandi, G.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; Fellous, R. El; Falvard, A.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J. C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Möllerud, R.; Nilsson, B.S.; Efthymiopoulos, I.; Kyriakis, A.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G. R.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Mermikides, M.; Sawyer, L.; Wasserbaech, S.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D’Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, F.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Have, I. ten; Lynch, J.G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K. M.; Smith, M. G.; Thompson, A. S.; Turnbull, R.M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Belk, A. T.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D.; Dornan, P. J.; Dugeay, S.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Nash, J.; Payne, D. G.; Phillips, M. J.; Sedgbeer, J. K.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kneringer, E.; Kühn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, Apoorva; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H. G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Aubert, J.J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, Ph.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D. N.; Catteneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A.W.; Lauber, J.; Lütjens, G.; Lütz, G.; Männer, W.; Richter, R.; Rotscheidt, H.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; Denis, R. St.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, P.; Jaffe, D. E.; Janot, P.; Kim, D.W.; Diberder, F. Le; Lefrançois, J.; Lutz, A. M.; Schune, M. H.; Veillet, J. J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bosisio, L.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Dell’Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Focardi, E.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Тенчини, Р.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Carter, J.M.; Green, M.G.; March, P.V.; Mir, L. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L.R.; Botterill, D.; Clifft, R. W.; Edgecock, R.; Edwards, M.; Fisher, S. M.; Jones, T. J.; Norton, P. R.; Salmon, D. P.; Thompson, J.C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Pérez, P.; Perrier, Frédéric; Rander, J.; Renardy, J. F.; Rosowsky, A.; Roussarie, A.; Schuller, J. P.; Schwindling, J.; Mohand, D. Si; Vallage, B.; Johnson, R.P.; Litke, A. M.; Taylor, G. N.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C. M.; Carney, R.; Cartwright, S. L.; Combley, F.; Hatfield, F.; Thompson, L.F.; Barberio, E.; Böhrer, A.; Brandt, Siegmund; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolík, L.; Marina, R. Della; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Cinabro, D.; Conway, J.; Cowen, D. F.; Feng, Z.; Ferguson, D.P.S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Jared, R. C.; LeClaire, B. W.; Lishka, C.; Pan, Y.; Pater, J. R.; Saadi, Y.; Sharma, V.; Schmitt, M.; Shi, Z. H.; Walsh, A. M.; Weber, F. V.; Wu, S. L.; Wu, X.; Zheng, M.; Zobernig, G.

doi:10.1016/0370-2693(93)90066-q

Cited by 21 publications

(11 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results are collected in the appendix. Figures 5,7,6,8 illustrate the level of agreement that has been reached for a few characteristic distributions.…”

Section: Comparison With Datamentioning

confidence: 85%

“…A consequence is that vacuum polarization eects produce an anti-screening of the bare QCD charges, which results in the strong coupling constant to diverge at large distances and to become small at short distances [5,6]. This explains why quarks are not observed as free particles [7] and at the same time renders perturbation theory applicable to describe processes involving large momentum transfers.…”

Section: Introductionmentioning

confidence: 99%

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QCD results from the study of hadronicZ-decays

Schmelling

1995

Phys. Scr.

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The high statistics data collected from hadronic Z-decays have lead to remarkable progress in the understanding of the dynamics of strong interactions. In addition to precision measurements of the strong coupling constant, the colour factors dening the gauge structure of QCD were determined with large accuracy. They are found to agree with the expectation for an unbroken SU(3) symmetry, t h us establishing unambigously the non-abelian nature of QCD. Higher order eects in many cases are known to next-to-leading logarithmic precision. Coherence eects as predicted in the framework of the modied leading-log approximation and local parton-hadron duality are experimentally well established. Studies of the hadronization process favour a chain-like production mechanism which bridges the gap between perturbative QCD as described by coherent parton shower models and the nal state hadrons. Submitted to Physica Scripta

show abstract

“…Results are collected in the appendix. Figures 5,7,6,8 illustrate the level of agreement that has been reached for a few characteristic distributions.…”

Section: Comparison With Datamentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

QCD results from the study of hadronicZ-decays

Schmelling

1995

Phys. Scr.

View full text Add to dashboard Cite

show abstract

“…This results in the strong coupling constant growing at large distances and becoming small at short distances [4,5]. This could possibly explain why quarks are not observed as free particles [6] and at the same time renders perturbation theory applicable to describe processes involving large momentum transfers.…”

Section: Contentsmentioning

confidence: 95%

“…Jets were tagged as b jets if they contained a lepton with momentum greater than 3 GeV/c and a transverse momentum with respect to the jet greater than 1.25 GeV/c, where the jet direction was determined without the lepton. A lepton in the highest energy jet denes the B sample, which contains 436 events and the avour composition is: 88% b, 6.1% c and 5% uds. The nal event sample, C, was selected by requiring the presence of a high momentum D in the highest energy jet.…”

Section: Discussionmentioning

confidence: 99%

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Studies of Quantum Chromodynamics with the ALEPH detector

Barate¹,

Buskulic²,

Décamp³

et al. 1998

Physics Reports

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319

301

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Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant, tests of its avour independence, tests of the SU(3) gauge structure of QCD, study of coherence eects, and measurements of single-particle inclusive distributions and two-particle correlations for many identied baryons and mesons.

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Search for heavy charged particles and for particles with anomalous charge in e+e− collisions at LEP

Akers¹,

Alexander²,

Allison³

et al. 1995

Z. Phys. C - Particles and Fields

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Using the OPAL data accumulated in 1991{1993 amounting to 74 pb 1 of integrated luminosity, corresponding to 1:64 10 6 selected multi-hadronic events, a search has been performed for charged particles with unusual mass or unusual charge. The mass was determined from a combination of momentum and ionization energy loss measurements. No isolation criteria were applied to the tracks examined, so that both isolated particles and particles produced in jets were valid candidates. For particles with charge Q=e = 1, one candidate with a mass of approximately 4:2 GeV=c 2 was found, which is compatible with the background rate expected according to a Monte Carlo simulation. The implications of this search for the mass limits of a conjectured stable or quasi-stable charged gluino composite (gqq 0 ) are discussed. Limits are also presented for the production of fractionally-charged particles with Q=e = 2=3 and 4=3 a s w ell as for particles with Q=e = 2.to be submitted to Zeit. Phys. C

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Search for particles with unexpected mass and charge in Z decays

Cited by 21 publications

References 20 publications

QCD results from the study of hadronicZ-decays

QCD results from the study of hadronicZ-decays

Studies of Quantum Chromodynamics with the ALEPH detector

Search for heavy charged particles and for particles with anomalous charge in e+e− collisions at LEP

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