Dijet angular distributions in direct and resolved photoproduction at HERA
Physics Letters B Elsevier 384:1-4 (1996) 401-413
Authors:
ZEUS Collaboration, M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, JR Okrasinski, J Repond, R Stanek, RL Talaga, H Zhang, MCK Mattingly, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, G Cara Romeo, G Castellini, L Cifarelli, F Cindolo, A Contin, M Corradi, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Polini, G Sartorelli, Y Zamora Garcia, A Zichichi, C Amelung, A Bornheim, J Crittenden, R Deffner, T Doeker, M Eckert, L Feld, A Frey, M Geerts, M Grothe, H Hartmann, K Heinloth, L Heinz, E Hilger, H-P Jakob, UF Katz, S Mengel, E Paul, M Pfeiffer, Ch Rembser, D Schramm, J Stamm, R Wedemeyer, S Campbell-Robson, A Cassidy, WN Cottingham, N Dyce, B Foster, S George, ME Hayes, GP Heath, HF Heath, D Piccioni, DG Roff, RJ Tapper, R Yoshida, M Arneodo, R Ayad, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, A Caldwell, N Cartiglia, Z Jing, W Liu, JA Parsons, S Ritz, F Sciulli, PB Straub, L Wai, S Yang, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, Z Jakubowski, MB Przybycie艅, M Zachara, L Zawiejski, L Adamczyk, B Bednarek, K Jele艅, D Kisielewska, T Kowalski, M Przybycie艅, E Rulikowska-Zar醛bska, L Suszycki, J Zaja抬c, Z Duli艅ski, A Kota艅ski, G Abbiendi, LAT Bauerdick, U Behrens, H Beier, JK Bienlein, G Cases, O Deppe, K Desler, G Drews, M Flasi艅ski, DJ Gilkinson, C Glasman, P G枚ttlicher, J Gro脽e-Knetter, T Haas, W Hain, D Hasell, H He脽ling, Y Iga, KF Johnson, P Joos, M Kasemann, R Klanner, W Koch, U K枚tz, H Kowalski, J Labs, A Ladage, B L枚hr, M L枚we, D L眉ke, J Mainusch, O Ma艅czak, J Milewski, T Monteiro, JST Ng, D Notz, K Ohrenberg, K Piotrzkowski, M Roco, M Rohde, J Rold谩n, U Schneekloth, W Schulz, F Selonke, B Surrow, T Vo脽, D Westphal, G Wolf, U Wollmer, C Youngman, W Zeuner, HJ Grabosch, A Kharchilava, SM Mari, A Meyer, S Schlenstedt, N Wulff, G Barbagli, E Gallo, P Pelfer, G Maccarrone, S De Pasquale, L Votano, A Bamberger, S Eisenhardt, T Trefzger, S W枚lfle, JT Bromley, NH Brook, PJ Bussey, AT Doyle, DH Saxon, LE Sinclair, ML Utley, AS Wilson, A Dannemann, U Holm, D Horstmann, R Sinkus, K Wick, BD Burow, L Hagge, E Lohrmann, G Poelz, W Schott, F Zetsche, TC Bacon, N Br眉mmer, I Butterworth, VL Harris, G Howell, BHY Hung, L Lamberti, KR Long, DB Miller, N Pavel, A Prinias, JK Sedgbeer, D Sideris, AF Whitfield, U Mallik, MZ Wang, SM Wang, JT Wu, P Cloth, D Filges, SH An, GH Cho, BJ Ko, SB Lee, SW Nam, HS Park, SK Park, S Kartik, H-J Kim, RR McNeil, W Metcalf, VK Nadendla, F Barreiro, JP Fernandez, R Graciani, JM Hern谩ndez, L Herv谩s, L Labarga, M Martinez, J del Peso, J Puga, J Terron, JF de Troc贸niz, F Corriveau, DS Hanna, J Hartmann, LW Hung, JN Lim, CG Matthews, PM Patel, M Riveline, DG Stairs, M St-Laurent, R Ullmann, G Zacek, T Tsurugai, V Bashkirov, BA Dolgoshein, A Stifutkin, GL Bashindzhagyan, PF Ermolov, LK Gladilin, Yu A Golubkov, VD Kobrin, IA Korzhavina, VA Kuzmin, O Yu Lukina, AS Proskuryakov, AA Savin, LM Shcheglova, AN Solomin, NP Zotov, M Botje, F Chlebana, J Engelen, M de Kamps, P Kooijman, A Kruse, A van Sighem, H Tiecke, W Verkerke, J Vossebeld, M Vreeswijk, L Wiggers, E de Wolf, R van Woudenberg, D Acosta, B Bylsma, LS Durkin, J Gilmore, C Li, TY Ling, P Nylander, IH Park, TA Romanowski, DS Bailey, RJ Cashmore, AM Cooper-Sarkar, RCE Devenish, N Harnew, M Lancaster, L Lindemann, JD McFall, C Nath, VA Noyes, A Quadt, JR Tickner, H Uijterwaal, R Walczak, DS Waters, FF Wilson, T Yip, A Bertolin, R Brugnera, R Carlin, F Dal Corso, M De Giorgi, U Dosselli, S Limentani, M Morandin, M Posocco, L Stanco, R Stroili, C Voci, F Zuin, J Bulmahn, RG Feild, BY Oh, JJ Whitmore, G D'Agostini, G Marini, A Nigro, E Tassi, JC Hart, NA McCubbin, TP Shah, E Barberis, T Dubbs, C Heusch, M Van Hook, W Lockman, JT Rahn, HF-W Sadrozinski, A Seiden, DC Williams, J Biltzinger, RJ Seifert, O Schwarzer, AH Walenta, G Zech, H Abramowicz, G Briskin, S Dagan, A Levy, JI Fleck, M Inuzuka, T ishii, M Kuze, S Mine, M Nakao, I Suzuki, K Tokushuku, K Umemori, S Yamada, Y Yamazaki, M Chiba, R Hamatsu, T Hirose, K Homma, S Kitamura, T Matsushita, K Yamauchi, R Cirio, M Costa, MI Ferrero, S Maselli, C Peroni, R Sacchi, A Solano, A Staino, M Dardo, DC Bailey, F Benard, M Brkic, C-P Fagerstroem, GF Hartner, KK Joo, GM Levman, JF Martin, RS Orr, S Polenz, CR Sampson, D Simmons, RJ Teuscher, JM Butterworth, CD Catterall, TW Jones, PB Kaziewicz, JB Lane, RL Saunders, J Shulman, MR Sutton, B Lu, LW Mo, W Bogusz, J Ciborowski, J Gajewski, G Grzelak, M Kasprzak, M Krzy偶anowski, K Muchorowski, RJ Nowak, JM Pawlak, T Tymieniecka, AK Wr贸blewski, JA Zakrzewski, AF 呕arnecki, M Adamus, C Coldewey, Y Eisenberg, D Hochman, U Karshon, D Revel, D Zer-Zion, WF Badgett, J Breitweg, D Chapin, R Cross, S Dasu, C Foudas, RJ Loveless, S Mattingly, DD Reeder, S Silverstein, WH Smith, A Vaiciulis, M Wodarczyk, S Bhadra, ML Cardy, WR Frisken, M Khakzad, WN Murray, WB Schmidke
Abstract:
Jet photoproduction, where the two highest transverse energy (ETjet) jets have ETjet above 6 GeV and a jet-jet invariant mass above 23 GeV, has been studied with the ZEUS detector at the HERA ep collider. Resolved and direct photoproduction samples have been separated. The cross section as a function of the angle between the jet-jet axis and the beam direction in the dijet rest frame has been measured for the two samples. The measured angular distributions differ markedly from each other. They agree with the predictions of QCD calculations, where the different angular distributions reflect the different spins of the quark and gluon exchanged in the hard subprocess.
