Multijet production at low x(Bj) in deep inelastic scattering at HERA

Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Jechow, M.; Pavel, N.; Yaguees, Molina A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Lacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Jakob, H. P.; Juengst, M.; Kind, O. M.; Nuncio Quiroz, A. E.; Paul, E.; Renner, R.; Samson, U.; Schoenberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Namsoo, T.; Capua, Marcella; Fazio, S.; Mastroberardino, Anna; Schioppa, M.; Susinno, G.; Tassi, Enrico; Kim, J. Y.; K. J., Ma; Ibrahim, Z. A.; Kamaluddin, B.; Wan, Abdullah W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bold, T.; Grabowska Bold, I.; Kisielewska, D.; Lukasik, J.; Przybycien, M.; Suszycki, L.; Kotanski, A.; Slominski, W.; Adler, V.; Behrens, U.; Bloch, I.; Blohm, C.; Bonato, A.; Borras, K.; Ciesielski, R.; Coppola, N.; Dossanov, A.; Drugakov, V.; Fourletova, J.; Geiser, A.; Gladkov, D.; Goettlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Horn, C.; Huettmann, A.; Kahle, B.; Katkov, I. I.; Klein, U.; Koetz, U.; Kowalski, H.; Lobodzinska, E.; Loehr, B.; Mankel, R.; Melzer Pellmann, I. A.; Miglioranzi, S.; Montanari, A.; Notz, D.; Rinaldi, L.; Roloff, P.; Rubinsky, I.; Santarnarta, R.; Schneekloth, U.; Spiridonov, A.; Stadie, H.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Ferrando, J.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schoerner Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; del Peso, J.; Ron, E.; Soares, M.; Terron, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Sosnovtse, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenkol, B. B.; Lukina, O. Y. u.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Buettner, C.; Caldwell, A.; Kollar, D.; Schmidke, W. B.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vazquez, M.; Wiggers, L.; Bruemmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper Sarkar, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Korcsak Gorzo, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, E.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; B. Y., Oh; Raval, A.; Ukleja, J.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Ingbir, R.; Kananov, S.; Levy, A.; Kuze, M.; Maeda, J.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Y. D., Ri; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Boutle, S. K.; Butterworth, J. M.; Gwenlan, C.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; Luzniak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; Zarnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Giller, I.; Hochman, D.; Karshon, U.; Rosin, M.; Brownson, E.; Danielson, T.; Everett, A.; Kcira, D.; Reeder, D. D.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, F. f.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.

doi:10.1016/j.nuclphysb.2007.05.027

Dijet and trijet production in deep inelastic ep scattering has been measured in the phase space region 10 < Q(2) < 100 GeV2 and 10(-4) < x(Bj) < 10(-2) using an integrated luminosity of 82 pb(-1) collected by the ZEUS experiment. The high statistics have made possible detailed studies of multijet production at low xBj. The dependence of dijet and trijet production on the kinematic variables Q(2) and x(Bj) and on the jet variables E-T,HCM(jet) and eta(jet)(LAB) is well described by perturbative QCD calculations which include NLO corrections. To investigate possible deviations with respect to the collinear factorisation approximation used in the standard pQCD approach, measurements of the correlations between the two jets with highest E-T,HCM(jet) have been made. At low x(Bj), measurements of dijet production with low azimuthal separation are reproduced by the perturbative QCD calculations provided that higher-order terms (O(alpha(3)(s))) are accounted for. Such terms increase the predictions of pQCD calculations by up to one order of magnitude when the two jets with the highest E-T,HCM(jet1,2) are not balanced in transverse momentum. This demonstrates the importance of higher-order corrections in the low-x(Bj) region. RI Wing, Matthew/C-2169-2008; IBRAHIM, ZAINOL ABIDIN/C-1121-2010; Fazio, Salvatore /G-5156-2010; WAN ABDULLAH, WAN AHMAD TAJUDDIN/B-5439-2010; Doyle, Anthony/C-5889-2009; Ferrando, James/A-9192-2012; Gladilin, Leonid/B-5226-2011

Dijet and trijet production in deep inelastic ep scattering has been measured in the phase space region 10 < Q(2) < 100 GeV(2) and 10(-4) < x(Bj) < 10(-2) using an integrated luminosity of 82 pb(-1) collected by the ZEUS experiment. The high statistics have made possible detailed studies of multijet production at low xBj. The dependence of dijet and trijet production on the kinematic variables Q(2) and x(Bj) and on the jet variables E(T,HCM)(jet) and eta(jet)(LAB) is well described by perturbative QCD calculations which include NLO corrections. To investigate possible deviations with respect to the collinear factorisation approximation used in the standard pQCD approach, measurements of the correlations between the two jets with highest E(T,HCM)(jet) have been made. At low x(Bj), measurements of dijet production with low azimuthal separation are reproduced by the perturbative QCD calculations provided that higher-order terms (O(alpha(3)(s))) are accounted for. Such terms increase the predictions of pQCD calculations by up to one order of magnitude when the two jets with the highest E(T,HCM)(jet1,2) are not balanced in transverse momentum. This demonstrates the importance of higher-order corrections in the low-x(Bj) region.