Studies of Quantum Chromodynamics with the ALEPH detector

Barate, R.; Buskulic, D.; Décamp, D.; Ghez, Philippe; Goy, C.; Lees, J. P.; Lucotte, A.; Minard, M.-N.; Nief, J.Y.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Comas, P.; Crespo, J.M.; Delfino, M.; Fernández, E.; Fernández-Bosman, M.; Garrido, Ll.; Rozas, A. Juste; Martı́nez, M.; Orteu, S.; Aranda, C. Padilla; Park, I.C.; Pascual, Á.; Perlas, J. A.; Riu, I.; Sanchez, F. J. Munoz; Teubert, F.; Colaleo, A.; Creanza, D.; Palma, M. De; Gelao, G.; Iaselli, G.; Mäggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X. T.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Alemany, R.; Bazarko, A.O.; Bright-Thomas, P.; Cattaneo, M.; Cerutti, F.; Drevermann, H.; Forty, R.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Löhse, T.; Lutters, G.; Mató, P.; Minten, A.; Miquel, R.; Mir, L. M.; Moneta, L.; Oest, T.; Pacheco, A.; Pusztaszeri, J. F.; Ranjard, F.; Rensing, P.; Rizzo, G.; Rolandi, G.; Schlatter, D.; Schmelling, M.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Ferdi, C.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J. C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J. M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B.S.; Rensch, B.; Wäänänen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G. R.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, F.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A.W.; Knowles, I. G.; Lynch, J.G.; O’Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K. M.; Teixeira-Dias, P.; Thompson, A. S.; Thomson, E.; Thomson, F.; Turnbull, R.M.; Becker, U.; Buchmüller, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, H.; Hepp, V.; Kluge, E. E.; Putzer, A.; Schmidt, M.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Girone, M.; Goodsir, S.; Martin, E. B.; Moutoussi, A.; Nash, J.A.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M.D.; Dissertori, G.; Hörtnagl, A.; Kühn, D.; Marie, L.K.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Williams, M.I.; Barczewski, T.; Galla, A.; Giehl, I.; Greene, A. M.; Hoffmann, C.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H. G.; Schmidt, H.; Steeg, F.; Gemmeren, P. van; Zeitnitz, C.; Aubert, J.J.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Coyle, P.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Leroy, O.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Berlich, R.; Blum, W.; Büscher, V.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lütjens, G.; Lütz, G.; Männer, W.; Moser, H. G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Chen, S.; Choi, Y.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, P.; Höcker, A.; Jachołkowska, A.; Jacquet, M.; Kim, D.W.; Diberder, F. Le; Lefrançois, J.; Lutz, A. M.; Nikolić, Irena; Park, H.J.; Schune, M. H.; Simion, S.; Veillet, J. J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell’Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Тенчини, Р.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Blair, G.A.; Bryant, L. M.; Chambers, J.T.; Green, M.G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; Wimmersperg-Toeller, J. H. von; Bertín, V.; Botterill, D.; Clifft, R. W.; Edgecock, T.R.; Haywood, S. J.; Maley, P.; Norton, P. R.; Thompson, J.C.; Wright, Alison; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; 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.; Black, S.N.; Dann, J.H.; Johnson, R.P.; Kim, H.Y.; Litke, A. M.; McNeil, M.A.; Taylor, G. P.; Beddall, A. J.; Booth, C.N.; Boswell, Rod; Brew, C.; Cartwright, S. L.; Combley, F.; Dawson, I.; Kelly, M.S.; Lehto, M. H.; Newton, W. M.; Reeve, J.; Thompson, L.F.; Böhrer, A.; Brandt, Siegmund; Cowan, G.; Feigl, Eric O.; Grupen, C.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, Pedro; Smolík, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Marina, R. Delia; Giannini, G.; Gobbo, B.; Musolino, G.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.R.; Elmer, P.; Feng, Z.; Ferguson, D.P.S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T.C.; Hayes, O.J.; Hu, H.; McNamara, P.A.; Nachtman, J. M.; Orejudos, W.; Pan, Y.; Saadi, Y.; Scott, I.; Walsh, J.; Wu, S. L.; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.

doi:10.1016/s0370-1573(97)00045-8

Cited by 311 publications

(319 citation statements)

References 200 publications

Supporting

Mentioning

300

Contrasting

Order By: Relevance

“…can be determined empirically by analyzing vacuum-to-vacuum current correlators constrained by data for e þ e − → charmonium and hadronic τ decays (40)(41)(42)(43)(44)(45)(46)(47). [Here we use units where ℏ ¼ c ¼ 1, and our flat-space metric is η μν ¼ diagð1; − 1; − 1; −1Þ.]…”

Section: Empirical Determinations Of the Gluon Condensatementioning

confidence: 99%

Condensates in quantum chromodynamics and the cosmological constant

Brodsky

Shrock

2010

Proc. Natl. Acad. Sci. U.S.A.

112

View full text Add to dashboard Cite

Casher and Susskind [Casher A, Susskind L (1974) Phys Rev 9:436-460] have noted that in the light-front description, spontaneous chiral symmetry breaking is a property of hadronic wavefunctions and not of the vacuum. Here we show from several physical perspectives that, because of color confinement, quark and gluon condensates in quantum chromodynamics (QCD) are associated with the internal dynamics of hadrons. We discuss condensates using condensed matter analogues, the Anti de Sitter/conformal field theory correspondence, and the Bethe-Salpeter-DysonSchwinger approach for bound states. Our analysis is in agreement with the Casher and Susskind model and the explicit demonstration of "in-hadron" condensates by Roberts and coworkers [Maris P, Roberts CD, Tandy PC (1998) Phys Lett B 420:267-273], using the Bethe-Salpeter-Dyson-Schwinger formalism for QCD-bound states. These results imply that QCD condensates give zero contribution to the cosmological constant, because all of the gravitational effects of the in-hadron condensates are already included in the normal contribution from hadron masses. where q is a light quark (i.e., a quark with current quark mass small compared with the quantum chromodynamics (QCD) scale QCD , where Λ QCD ≃ 300 MeV. These condensates are conventionally considered to be properties of the QCD vacuum and hence are constant throughout space-time. A consequence of the existence of such vacuum condensates is contributions to the cosmological constant from these condensates that are 10 45 times larger than the observed value. If this disagreement were really true, it would be an extraordinary conflict between the experiment and the standard model.A very different perspective on hadronic condensates was first presented in a seminal paper by Casher and Susskind (1) published in 1974, see also ref. 2. These authors argued that "spontaneous symmetry breaking must be attributed to the properties of the hadron's wavefunction and not to the vacuum" (1). The Casher-Susskind argument is based on Weinberg's infinite momentum frame (3) Hamiltonian formalism of hadronic physics, which is equivalent to light-front (LF) quantization and Dirac's front form (4) rather than the usual instant form. Casher and Susskind also presented a specific model in which spontaneous chiral symmetry breaking occurs within the confines of the hadron wavefunction due to a phase change supported by the infinite number of quark and quark pairs in the LF wavefunction. In fact, the Regge behavior of hadronic structure functions requires that LF Fock states of hadrons have Fock states with an infinite number of quark and gluon partons (5-7). Thus, in contrast to formal discussions in statistical mechanics, infinite volume is not required for a phase transition in relativistic quantum field theories.Spontaneous chiral symmetry breaking in QCD is often analyzed by means of an approximate solution of the Dyson-Schwinger equation for a massless quark propagator; if the running coupling α s ¼ g 2 s ∕ð4πÞ exceeds a value of order 1, th...

show abstract

Section: Empirical Determinations Of the Gluon Condensatementioning

confidence: 99%

Condensates in quantum chromodynamics and the cosmological constant

Brodsky

Shrock

2010

Proc. Natl. Acad. Sci. U.S.A.

112

View full text Add to dashboard Cite

show abstract

“…1 There are alternative approaches to estimate hadronization corrections that address both theoretical [42] and experimental [16,43] aspects of this procedure.…”

Section: Jhep11(2010)050mentioning

confidence: 99%

NLO QCD corrections to five-jet production at LEP and the extraction of α s (M Z )

Frederix

Frixione

Melnikov

et al. 2010

J. High Energ. Phys.

View full text Add to dashboard Cite

Abstract:The highest exclusive jet multiplicity studied at LEP experiments is five. In this paper we compute the next-to-leading order QCD corrections to e + e − annihilation to five jets, essentially closing the (pure) perturbative QCD studies of exclusive jetty final states at LEP. We compare fixed-order perturbative results with ALEPH data. We estimate hadronization corrections to five-jet observables using the event generator SHERPA, which employs the CKKW procedure to combine a reliable perturbative treatment of highmultiplicity jet final states with parton showers. We show that a competitive value of the strong coupling constant α s (M Z ) = 0.1156 +0.0041 −0.0034 can be extracted from the distribution of the five-jet resolution parameter and the five-jet rate at LEP1 and LEP2.

show abstract

“…The method employed to tune the parameters in this study can be found in [2]. It is based on a linear and iterative approach and allows the simultaneous variation of many parameters.…”

Section: Tuning Methodsmentioning

confidence: 99%

“…It has been developed and extensively used within ALEPH and has been adapted for pp or ppbar reactions [7]. The parton shower and hadronisation parameters have been determined independently from fits to e+e-→ hadrons data collected at Z 0 pole by the ALEPH experiment [2].…”

Section: Tuning Methodsmentioning

confidence: 99%