Inclusive-jet cross sections in NC DIS at HERA and a comparison of the kT, anti-kT and SIScone jet algorithms

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 691:3 (2010) 127-137

Authors:

H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, T Bołd, EG Boos, M Borodin, K Borras, D Boscherini, D Bot, SK Boutle, I Brock, E Brownson, R Brugnera, N Brümmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, JM Butterworth, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, FD Corso, J de Favereau, J de Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, S Fourletov, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, LK Gladilin, D Gladkov, C Glasman, O Gogota, Y Golubkov, P Göttlicher, I Grabowska-Bołd, J Grebenyuk, I Gregor

Abstract:

For the first time, differential inclusive-jet cross sections have been measured in neutral current deep inelastic ep scattering using the anti-kT and SIScone algorithms. The measurements were made for boson virtualities Q2>125 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1 and the jets were identified in the Breit frame. The performance and suitability of the jet algorithms for their use in hadron-like reactions were investigated by comparing the measurements to those performed with the kT algorithm. Next-to-leading-order QCD calculations give a good description of the measurements. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(αs3) terms. Values of αs(MZ) were extracted from the data; the results are compatible with and have similar precision to the value extracted from the kT analysis. © 2010 Elsevier B.V.

A QCD analysis of ZEUS diffractive data

Nuclear Physics B 831:1-2 (2010) 1-25

Authors:

S Chekanov, M Derrick, S Magill, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, L Bellagamba, D Boscherini, A Bruni, G Bruni, F Cindolo, M Corradi, G Iacobucci, A Margotti, R Nania, A Polini, S Antonelli, M Basile, M Bindi, L Cifarelli, A Contin, S De Pasquale, G Sartorelli, A Zichichi, D Bartsch, I Brock, H Hartmann, E Hilger, HP Jakob, M Jüngst, AE Nuncio-Quiroz, E Paul, U Samson, V Schönberg, R Shehzadi, M Wlasenko, JD Morris, M Kaur, P Kaur, I Singh, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, ZA Ibrahim, FM Idris, B Kamaluddin, WAT Wan Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, K Olkiewicz, B Pawlik, P Stopa, L Zawiejski, L Adamczyk, T Bołd, I Grabowska-Bołd, D Kisielewska, J Łukasik, M Przybycień, L Suszycki, A Kotański, W Słomiński, O Bachynska, O Behnke, J Behr, U Behrens, C Blohm, K Borras, D Bot, R Ciesielski, N Coppola, S Fang, A Geiser, P Göttlicher, J Grebenyuk, I Gregor, T Haas, W Hain, A Hüttmann, F Januschek, B Kahle, II Katkov, U Klein, U Kötz, H Kowalski, V Libov, M Lisovyi

Abstract:

ZEUS inclusive diffractive-cross-section measurements have been used in a DGLAP next-to-leading-order QCD analysis to extract the diffractive parton distribution functions. Data on diffractive dijet production in deep inelastic scattering have also been included to constrain the gluon density. Predictions based on the extracted parton densities are compared to diffractive charm and dijet photoproduction data. © 2010 Elsevier B.V.

Measurement of beauty production in DIS and F_2^bbbar extraction at ZEUS

(2010)

Authors:

ZEUS collaboration, H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, T Bold, EG Boos, M Borodin, K Borras, D Boscherini, D Bot, SK Boutle, I Brock, E Brownson, R Brugnera, N Bruemmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, JM Butterworth, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, F Dal Corso, J de Favereau, J del Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, S Fourletov, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, LK Gladilin, D Gladkov, C Glasman, O Gogota, Yu A Golubkov, P Goettlicher, I Grabowska-Bold, J Grebenyuk, I Gregor, G Grigorescu, G Grzelak, C Gwenlan, T Haas, W Hain, R Hamatsu, JC Hart, H Hartmann, G Hartner, E Hilger, D Hochman, U Holm, R Hori, K Horton, A Huettmann, G Iacobucci, ZA Ibrahim, Y Iga, R Ingbir, M Ishitsuka, H-P Jakob, F Januschek, M Jimenez, TW Jones, M Juengst, I Kadenko, B Kahle, B Kamaluddin, S Kananov, T Kanno, U Karshon, F Karstens, II Katkov, M Kaur, P Kaur, A Keramidas, LA Khein, JY Kim, D Kisielewska, S Kitamura, R Klanner, U Klein, E Koffeman, D Kollar, P Kooijman, Ie Korol, IA Korzhavina, A Kotanski, U Koetz, H Kowalski, P Kulinski, O Kuprash, M Kuze, VA Kuzmin, A Lee, BB Levchenko, A Levy, V Libov, S Limentani, TY Ling, M Lisovyi, E Lobodzinska, W Lohmann, B Loehr, E Lohrmann, JH Loizides, KR Long, A Longhin, D Lontkovskyi, O Yu Lukina, P Luzniak, J Maeda, S Magill, I Makarenko, J Malka, R Mankel, A Margotti, G Marini, JF Martin, A Mastroberardino, T Matsumoto, MCK Mattingly, I-A Melzer-Pellmann, S Miglioranzi, F Mohamad Idris, V Monaco, A Montanari, JD Morris, B Musgrave, K Nagano, T Namsoo, R Nania, D Nicholass, A Nigro, Y Ning, U Noor, D Notz, RJ Nowak, AE Nuncio-Quiroz, BY Oh, N Okazaki, K Oliver, K Olkiewicz, Yu Onishchuk, O Ota, K Papageorgiu, A Parenti, E Paul, JM Pawlak, B Pawlik, PG Pelfer, A Pellegrino, W Perlanski, H Perrey, K Piotrzkowski, P Plucinski, NS Pokrovskiy, A Polini, AS Proskuryakov, M Przybycien, A Raval, DD Reeder, B Reisert, Z Ren, J Repond, YD Ri, A Robertson, P Roloff, E Ron, I Rubinsky, M Ruspa, R Sacchi, A Salii, U Samson, G Sartorelli, AA Savin, DH Saxon, M Schioppa, S Schlenstedt, P Schleper, WB Schmidke, U Schneekloth, V Schoenberg, T Schoerner-Sadenius, J Schwartz, F Sciulli, LM Shcheglova, R Shehzadi, S Shimizu, I Singh, IO Skillicorn, W Slominski, WH Smith, V Sola, A Solano, D Son, V Sosnovtsev, A Spiridonov, H Stadie, L Stanco, A Stern, TP Stewart, A Stifutkin, P Stopa, S Suchkov, G Susinno, L Suszycki, J Sztuk, D Szuba, J Szuba, AD Tapper, E Tassi, J Terron, T Theedt, H Tiecke, K Tokushuku, O Tomalak, J Tomaszewska, T Tsurugai, M Turcato, T Tymieniecka, C Uribe-Estrada, M Vazquez, A Verbytskyi, V Viazlo, NN Vlasov, O Volynets, R Walczak, WAT Wan Abdullah, JJ Whitmore, J Whyte, L Wiggers, M Wing, M Wlasenko, G Wolf, H Wolfe, K Wrona, AG Yagues-Molina, S Yamada, Y Yamazaki, R Yoshida, C Youngman, AF Zarnecki, L Zawiejski, O Zenaiev, W Zeuner, BO Zhautykov, N Zhmak, C Zhou, A Zichichi, M Zolko, DS Zotkin, Z Zulkapli

Investigation of the role of plasma channels as waveguides for laser-wakefield accelerators

New Journal of Physics 12 (2010)

Authors:

TPA Ibbotson, N Bourgeois, TP Rowlands-Rees, LS Caballero, SI Bajlekov, PA Walker, S Kneip, M Spd, SR Nagel, P Caj, N Delerue, G Doucas, D Urner, O Chekhlov, RJ Clarke, E Divall, K Ertel, P Foster, SJ Hawkes, CJ Hooker, B Parry, PP Rajeev, MJV Streeter, SM Hooker

Abstract:

The role of plasma channels as waveguides for laser-wakefield accelerators is discussed in terms of the results of experiments performed with the Astra-Gemini laser, numerical simulations using the code WAKE, and the theory of self-focusing and self-guiding of intense laser beams. It is found that at a given electron density, electron beams can be accelerated using lower laser powers in a waveguide structure than in a gas-jet or cell. The transition between relativistically self-guided and channel-assisted guiding is seen in the simulations and in the behaviour of the production of electron beams. We also show that by improving the quality of the driving laser beam the threshold laser energy required to produce electron beams can be reduced by a factor of almost 2. The use of an aperture allows the production of a quasi-monoenergetic electron beam of energy 520 MeV with an input laser power of only 30 TW. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Measurement of isolated photon production in deep inelastic ep scattering

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 687:1 (2010) 16-25

Authors:

S Chekanov, M Derrick, S Magill, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, L Bellagamba, D Boscherini, A Bruni, G Bruni, F Cindolo, M Corradi, G Iacobucci, A Margotti, R Nania, A Polini, S Antonelli, M Basile, M Bindi, L Cifarelli, A Contin, S De Pasquale, G Sartorelli, A Zichichi, D Bartsch, I Brock, H Hartmann, E Hilger, HP Jakob, M Jüngst, AE Nuncio-Quiroz, E Paul, U Samson, V Schönberg, R Shehzadi, M Wlasenko, JD Morris, M Kaur, P Kaur, I Singh, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, ZA Ibrahim, FM Idris, B Kamaluddin, WATW Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, K Olkiewicz, B Pawlik, P Stopa, L Zawiejski, L Adamczyk, T Bołd, I Grabowska-Bołd, D Kisielewska, J Łukasik, M Przybycień, L Suszycki, A Kotański, W Słomiński, O Bachynska, O Behnke, J Behr, U Behrens, C Blohm, K Borras, D Bot, R Ciesielski, N Coppola, S Fang, A Geiser, P Göttlicher, J Grebenyuk, I Gregor, T Haas, W Hain, A Hüttmann, F Januschek, B Kahle, II Katkov, U Klein, U Kötz, H Kowalski, V Libov, M Lisovyi

Abstract:

Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320 pb - 1. Measurements were made in the isolated-photon transverse-energy and pseudorapidity ranges 4 < E Tγ < 15 GeV and - 0.7 < η γ < 0.9 for exchanged photon virtualities, Q 2, in the range 10 < Q 2 < 350 GeV 2 and for invariant masses of the hadronic system W X > 5 GeV. Differential cross sections are presented for inclusive isolated photon production as functions of Q 2, x, E Tγ and η γ. Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range. © 2010 Elsevier B.V.