Charged particle multiplicity in three-jet events and two-gluon systems

Summary, in English

The charged particle multiplicity in hadronic three-jet events from Z decays is investigated. The topology dependence of the event multiplicity is found to be well described by a modified leading logarithmic prediction. A parameter fit of the prediction to the data yields a measurement of the colour factor ratio C-A/C-F with the result C-A/C-F = 2.261 +/- 0.014(stat). +/- 0.036(exp). +/- 0-066(theo). in agreement with the SU(3) expectation of QCD. The quark-related contribution to the event multiplicity is subtracted from the three-jet event multiplicity resulting in a measurement of the multiplicity of two-gluon colour-singlet states over a wide energy range. The ratios r = N-gg(s)/Ng (g) over bar (s) of the gluon and quark multiplicities and r((1)) = N'(gg)(s)/N'g (g) over bar (s) of their derivatives are compared with perturbative calculations. While a good agreement between calculations and data is observed for r((1)), larger deviations are found for r indicating that non-perturbative effects are more important for r than for r((1)).

• Author: J Abdallah; P Abreu; W Adam; P Adzic; T Albrecht; T Alderweireld; R Alemany-Fernandez; T Allmendinger; PP Allport; U Amaldi; N Amapane; S Amato; E Anashkin; A Andreazza; S Andringa; N Anjos; P Antilogus; WD Apel; Y Arnoud; S Ask; B Asman; JE Augustin; A Augustinus; P Baillon; A Ballestrero; P Bambade; R Barbier; D Bardin; GJ Barker; A Baroncelli; A Battaglia; M Baubillier; KH Becks; M Begalli; A Behrmann; E Ben-Haim; N Benekos; A Benvenuti; C Berat; M Berggren; L Berntzon; D Bertrand; M Besancon; N Besson; D Bloch; A Blom; A Bluj; A Bonesini; M Boonekamp; PSL Booth; G Borisov; O Botner; B Bouquet; TJV Bowcock; I Bovko; M Bracko; R Brenner; E Brodet; P Bruckman; JM Brunet; P Buschmann; A Calvi; T Camporesi; V Canale; F Carena; N Castro; F Cavallo; M Chapkin; P Charpentier; P Checchia; R Chierici; P Chliapnikov; J Chudoba; SU Chung; K Cieslik; P Collins; R Contri; C Cosme; F Cossutti; MJ Costa; D Crennell; J Cuevas; J D'Hondt; J Dalmau; T da Silva; W Da Silva; G Della Ricca; A De Angelis; W De Boer; C De Clercq; B De Lotto; N De Maria; A De Min; L de Paula; L Di Ciaccio; A Di Simone; K Doroba; J Drees; G Eigen; T Ekelof; A Ellert; M Elsing; MCE Santo; G Fanourakis; D Fassouliotis; M Feindt; J Fernandez; A Ferrer; F Ferro; U Flagmeyer; H Foeth; E Fokitis; F Fulda-Quenzer; J Fuster; M Gandelman; C Garcia; P Gavillet; E Gazis; R Gokieli; B Golob; G Gomez-Ceballos; P Goncalves; E Graziani; G Grosdidier; K Grzelak; J Guy; C Haag; A Hallgren; K Hamacher; K Hamilton; S Haug; F Hauler; Vincent Hedberg; M Hennecke; H Herr; J Hoffman; SO Holmgren; PJ Holt; MA Houlden; K Hultqvist; JN Jackson; Göran Jarlskog; P Jarry; D Jeans; EK Johansson; PD Johansson; P Jonsson; C Joram; L Jungermann; F Kapusta; S Katsanevas; E Katsoufis; G Kernel; BP Kersevan; U Kerzel; BT King; NJ Kjaer; P Kluit; P Kokkinias; C Kourkoumelis; O Kouznetsov; Z Krumstein; M Kucharczyk; J Lamsa; G Leder; F Ledroit; L Leinonen; R Leitner; J Lemonne; V Lepeltier; T Lesiak; W Liebig; D Liko; A Lipniacka; JH Lopes; JM Lopez; D Loukas; P Lutz; L Lyons; J MacNaughton; A Malek; S Maltezos; F Mandl; J Marco; R Marco; B Marechal; M Margoni; JC Marin; C Mariotti; A Markou; C Martinez-Rivero; J Masik; N Mastroyiannopoulos; F Matorras; C Matteuzzi; F Mazzucato; M Mazzucato; R McNulty; C Meroni; E Migliore; W Mitaroff; U Mjoernmark; T Moa; M Moch; K Moenig; R Monge; J Montenegro; D Moraes; S Moreno; P Morettini; U Mueller; K Muenich; M Mulders; L Mundim; W Murray; B Muryn; G Myatt; T Myklebust; M Nassiakou; F Navarria; K Nawrocki; R Nicolaidou; M Nikolenko; A Oblakowska-Mucha; V Obraztsov; A Olshevski; A Onofre; R Orava; K Osterberg; A Ouraou; A Oyanguren; M Paganoni; S Paiano; JP Palacios; H Palka; TD Papadopoulou; L Pape; C Parkes; F Parodi; U Parzefall; A Passeri; O Passon; L Peralta; V Perepelitsa; A Perrotta; A Petrolini; J Piedra; L Pieri; F Pierre; M Pimenta; E Piotto; T Podobnik; V Poireau; ME Pol; G Polok; V Pozdniakov; N Pukhaeva; A Pullia; J Rames; A Read; P Rebecchi; J Rehn; D Reid; R Reinhardt; P Renton; F Richard; J Ridky; M Rivero; A Romero; P Ronchese; P Roudeau; T Rovelli; V Ruhlmann-Kleider; D Ryabtchikov; A Sadovsky; L Salmi; J Salt; C Sander; A Savoy-Navarro; U Schwickerath; A Segar; R Sekulin; A Siebel; A Sisakian; G Smadja; Oxana Smirnova; A Sokolov; A Sopczak; R Sosnowski; T Spassov; A Stanitzki; A Stocchi; J Strauss; B Stugu; M Szczekowski; M Szeptycka; T Szumlak; T Tabarelli; AC Taffard; F Tegenfeldt; J Timmermans; L Tkatchev; M Tobin; S Todorovova; B Tome; A Tonazzo; P Tortosa; P Travnicek; D Treille; G Tristram; M Trochimczuk; C Troncon; AL Turluer; IA Tyapkin; P Tyupkin; S Tzamarias; V Uvarov; G Valenti; P Van Dam; J Van Eldik; N van Remortel; I Van Vulpen; G Vegni; F Veloso; W Venus; P Verdier; V Verzi; D Vilanova; L Vitale; V Vrba; H Wahlen; AJ Washbrook; C Weiser; D Wicke; J Wickens; G Wilkinson; M Winter; A Witek; O Yushchenko; A Zalewska; P Zalewski; D Zavrtanik; V Zhuravlov; NI Zimin; A Zintchenko; M Zupan
• Department/s: Particle and nuclear physics
• Publishing year: 2005
• Language: English
• Pages: 311-331
• Publication/Series: European Physical Journal C. Particles and Fields
• Volume: 44
• Issue: 3
• Links: http://dx.doi.org/10.1140/epjc/s2005-02390-x
• Document type: Journal article
• Publisher: Springer
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1434-6044