Measurement of three-jet distributions in photoproduction at HERA

Breitweg, J Chekanov, S Derrick, M Krakauer, D Magill, S Musgrave, B Repond, J Stanek, R Yoshida, R Mattingly, MCK Abbiendi, G Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Coppola, N Corradi, M De Pasquale, S Giusti, P Iacobucci, G Laurenti, C Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Kappes, A Katz, UF Kerger, R Paul, E Pfeiffer, M Schnurbusch, H Weber, A Wieber, H Bailey, DS Barret, O Cottingham, WN Foster, B Hall-Wilton, R Heath, GP Heath, HF McFall, JD Piccioni, D Scott, J Tapper, RJ Capua, M Mastroberardino, A Schioppa, M Susinno, G Jeoung, HY Kim, JY Lee, JH Lim, IT Ma, KJ Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Mellado, B Parsons, JA Ritz, S Sacchi, R Sampson, S Sciulli, F Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Figiel, J Klimek, K Przybycien, MB Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowal, AM Kowalski, T Przybycien, M Rulikowska-Zarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Burgard, C Desler, K Drews, G Fricke, U Goebel, F Gottlicher, P Graciani, R Haas, T Hain, W Hartner, GF Hasell, D Hebbel, K Johnson, KF Kasemann, M Koch, W Kootz, U Kowalski, H Lindemann, L Lohr, B Martiinez, M Milewski, J Milite, M Monteiro, T Notz, D Pellegrino, A Pelucchi, F Piotrzkowski, K Rohde, M Roldan, J Ryan, JJ Saull, PRB Savin, AA Schneekloth, U Schwarzer, O Selonke, F Sievers, M Stonjek, S Surrow, B Tassi, E Westphal, D Wolf, G Wollmer, U Youngman, C Zeuner, W Burow, BD Coldewey, C Grabosch, HJ Viani, ALD Meyer, A Monig, K Schlenstedt, S Straub, PB Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Raach, H Wolfle, S Brook, NH Bussey, PJ Doyle, AT Lee, SW Macdonald, N McCance, GJ Saxon, DH Sinclair, LE Skillicorn, IO Strickland, E Waugh, R Bohnet, I Gendner, N Holm, U Meyer-Larsen, A Salehi, H Wick, K Garfagnini, A Gialas, I Gladilin, LK Kcira, D Klanner, R Lohrmann, E Poelz, G Zetsche, F Bacon, TC Cole, JE Howell, GC Lamberti, L Long, KR Miller, DB Prinias, A Sedgbeer, JK Sideris, D Tapper, AD Walker, R Mallik, T Wang, SM Cloth, P Filges, D Ishii, T Kuze, M Suzuki, I Tokushuku, K Yamada, S Yamauchi, K Yamazaki, Y Ahn, SH An, SH Hong, SJ Lee, SB Nam, SW Park, SK Lim, H Park, IH Son, D Barreiro, F Fernandez, JP Garcia, G Glasman, C Hernandez, JM Labarga, L del Peso, J Puga, J Redondo, I Terron, J Corriveau, F Hanna, DS Hartmann, J Murray, WN Ochs, A Padhi, S Pinciuc, C Riveline, M Stairs, DG St-Laurent, M Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Engelen, J Koffeman, E Kooijman, P van Sighem, A Tiecke, H Tuning, N Verkerke, W Vossebeld, J Wiggers, L de Wolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Blaikley, HE Cashmore, RJ Cooper-Sarkar, AM Devenish, RCE Edmonds, JK Grosse-Knetter, J Harnew, N Matsushita, T Noyes, VA Quadt, A Ruske, O Sutton, MR Walczak, R Waters, DS Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Iannotti, L Oh, BY Okrasinski, JR Toothacker, WS Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Raso, M Cormack, C Hart, JC McCubbin, NA Shah, TP Epperson, D Heusch, C Sadrozinski, HFW Seiden, A Wichmann, R Williams, DC Pavel, N Abramowicz, H Briskin, G Dagan, S Kananov, S Levy, A Abe, T Fusayasu, T Inuzuka, M Nagano, K Umemori, K Yamashita, T Hamatsu, R Hirose, T Homma, K Kitamura, S Nishimura, T Arneodo, M Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Ruspa, M Solano, A Staiano, A Dardo, M Bailey, DC Fagerstroem, CP Galea, R Koop, T Levman, GM Martin, JF Orr, RS Polenz, S Sabetfakhri, A Simmons, D Butterworth, JM Catterall, CD Hayes, ME Heaphy, EA Jones, TW Lane, JB Wing, M Ciborowski, J Grzelak, G Nowak, RJ Pawlak, JM Pawlak, R Smalska, B Tymieniecka, T Wroblewski, AK Zakrzewski, JA Zarnecki, AF Adamus, M Gadaj, T Deppe, O Eisenberg, Y Hochman, D Karshon, U Badgett, WF Chapin, D Cross, R Foudas, C Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wildschek, T Wodarczyk, M Deshpande, A Dhawan, S Hughes, VW Bhadra, S Frisken, WR Khakzad, M Menary, S Schmidke, WB

J. Breitweg et al., Measurement of three-jet distributions in photoproduction at HERA, PHYS LETT B, 443(1-4), 1998, pp. 394-408

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Physics

PHYSICS LETTERS B

0370-2693 → ACNP

443

1-4

1998

394 - 408

ISI

0370-2693(199812)443:1-4<394:MOTDIP>2.0.ZU;2-D

The cross section for the photoproduction of events containing three jets w ith a three-jet invariant mass of M-3J > 50 GeV has been measured with the ZEUS detector at HERA. The three-jet angular distributions are inconsistent with a uniform population of the available phase space but are well descri bed by parton shower models and O(alpha alpha(s)(2)) pQCD calculations. Com parisons with the parton shower model indicate a strong contribution from i nitial state radiation as well as a sensitivity to the effects of colour co herence. (C) 1998 Elsevier Science B.V. All rights reserved.