1. Inclusive photoproduction of neutral pions in the photon hemisphere at HERA
- Author
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Adloff, C, Andreev, V, Andrieu, B, Arkadov, V, Astvatsatourov, A, Ayyaz, I, Babaev, A, Bahr, J, Baranov, P, Barrelet, E, Bartel, W, Bassler, U, Bate, P, Beglarian, A, Behnke, O, Beier, C, Belousov, A, Benisch, T, Berger, C, Bernardi, G, Berndt, T, Bertrand-Coremans, G, Bizot, JC, Borras, K, Boudry, V, Braunschweig, W, Brisson, V, Broker, HB, Brown, DP, Bruckner, W, Bruel, P, Bruncko, D, Burger, J, Busser, FW, Bunyatyan, A, Burkhardt, H, Burrage, A, Buschhorn, G, Campbell, AJ, Cao, J, Carli, T, Caron, S, Chabert, E, Clarke, D, Clerbaux, B, Collard, C, Contreras, JG, Coughlan, JA, Cousinou, MC, Cox, BE, Cozzika, G, Cvach, J, Dainton, JB, Dau, WD, Daum, K, David, M, Davidsson, M, Delcourt, B, Delerue, N, Demirchyan, R, De Roeck, A, De Wolf, EA, Diaconu, C, Dixon, P, Dodonov, V, Donovan, KT, Dowell, JD, Droutskoi, A, Duprel, C, Ebert, J, Eckerlin, G, Eckstein, D, Efremenko, V, Egli, S, Eichler, R, Eisele, F, Eisenhandler, E, Ellerbrock, M, Elsen, E, Erdmann, M, Faulkner, PJW, Favart, L, Fedotov, A, Felst, R, Ferencei, J, Ferrarotto, F, Ferron, S, Fleischer, M, Flugge, G, Fomenko, A, Foresti, I, Formanek, J, Foster, JM, Franke, G, Gabathuler, E, Gabathuler, K, Garvey, J, Gassner, J, Gayler, J, Gerhards, R, Ghazaryan, S, Glazov, A, Goerlich, L, Gogitidze, N, Goldberg, M, Goodwin, C, Grab, C, Grassler, H, Greenshaw, T, Grindhammer, G, Hadig, T, Haidt, D, Hajduk, L, Haustein, V, Haynes, WJ, Heinemann, B, Heinzelmann, G, Henderson, RCW, Hengstmann, S, Henschel, H, Heremans, R, Herrera, G, Herynek, I, Hilgers, M, Hiller, KH, Hilton, CD, Hladky, J, Hoting, P, Hoffmann, D, Hoprich, W, Horisberger, R, Hurling, S, Ibbotson, M, Issever, C, Jacquet, M, Jaffre, M, Janauschek, L, Jansen, DM, Janssen, X, Jemanov, V, Jonsson, L, Johnson, DP, Jones, MAS, Jung, H, Kastli, HK, Kant, D, Kapichine, M, Karlsson, M, Karschnick, O, Kaufmann, O, Kausch, M, Keil, F, Keller, N, Kennedy, J, Kenyon, IR, Kermiche, S, Kiesling, C, Klein, M, Kleinwort, C, Knies, G, Koblitz, B, Kolanoski, H, Kolya, SD, Korbel, V, Kostka, P, Kotelnikov, SK, Krasny, MW, Krehbiel, H, Kroseberg, J, Krucker, D, Kruger, K, Kupper, A, Kuhr, T, Kurca, T, Kutuev, R, Lachnit, W, Lahmann, R, Lamb, D, Landon, MPJ, Lange, W, Lastovicka, T, Lebedev, A, Leissner, B, Lemaitre, V, Lemrani, R, Lendermann, V, Levonian, S, Lindstroem, M, Lobo, G, Lobodzinska, E, Lobodzinski, B, Loktionova, N, Lubimov, V, Luders, S, Luke, D, Lytkin, L, Magnussen, N, Mahlke-Kruger, H, Malden, N, Malinovski, E, Malinovski, I, Maracek, R, Marage, P, Marks, J, Marshall, R, Martyn, HU, Martyniak, J, Maxfield, SJ, Mehta, A, Meier, K, Merkel, P, Metlica, F, Meyer, A, Meyer, H, Meyer, J, Meyer, PO, Mikocki, S, Milstead, D, Mkrtchyan, T, Mohr, R, Mohrdieck, S, Mondragon, MN, Moreau, F, Morozov, A, Morris, JV, Muller, D, Muller, K, Murin, P, Nagovizin, V, Naroska, B, Naumann, J, Naumann, T, Negri, I, Nellen, G, Newman, PR, Nicholls, TC, Niebergall, F, Niebuhr, C, Nix, O, Nowak, G, Nunnemann, T, Olsson, JE, Ozerov, D, Panassik, V, Pascaud, C, Passaggio, S, Patel, GD, Perez, E, Phillips, JP, Pitzl, D, Poschl, R, Potachnikova, I, Povh, B, Rabbertz, K, Radel, G, Rauschenberger, J, Reimer, P, Reisert, B, Reyna, D, Riess, S, Rizvi, E, Robmann, P, Roosen, R, Rostovtsev, A, Royon, C, Rusakov, S, Rybicki, K, Sankey, DPC, Scheins, J, Schilling, FP, Schleif, S, Schleper, P, Schmidt, D, Schoeffel, L, Schoning, A, Schorner, T, Schroder, V, Schultz-Coulon, HC, Sedlak, K, Sefkow, F, Shekelyan, V, Sheviakov, I, Shtarkov, LN, Siegmon, G, Sievers, P, Sirois, Y, Sloan, T, Smirnov, P, Smith, M, Solochenko, V, Soloviev, Y, Spaskov, V, Specka, A, Spitzer, H, Stamen, R, Steinhart, J, Stella, B, Stellberger, A, Stiewe, J, Straumann, U, Struczinski, W, Sutton, JP, Swart, M, Tasevsky, M, Tchernyshov, V, Tchetchelnitski, S, Thompson, G, Thompson, PD, Tobien, N, Traynor, D, Truol, P, Tsipolitis, G, Turnau, J, Turney, JE, Tzamariudaki, E, Udluft, S, Usik, A, Valkar, S, Valkarova, A, Vallee, C, Van Mechelen, P, Vazdik, Y, von Dombrowski, S, Wacker, K, Wallny, R, Walter, T, Waugh, B, Weber, G, Weber, M, Wegener, D, Wegner, A, Wengler, T, Werner, M, White, G, Wiesand, S, Wilksen, T, Winde, M, Winter, GG, Wissing, C, Wobisch, M, Wollatz, H, Wunsch, E, Zacek, J, Zalesak, J, Zhang, Z, Zhokin, A, Zomer, F, Zsembery, J, zur Nedden, M, Collaboration, H, Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), H1, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and H1 Collaboration
- Subjects
Physics ,Particle physics ,Photon ,Physics and Astronomy (miscellaneous) ,Meson ,010308 nuclear & particles physics ,Monte Carlo method ,FOS: Physical sciences ,Context (language use) ,HERA ,01 natural sciences ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,symbols.namesake ,Pion ,0103 physical sciences ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,symbols ,Feynman diagram ,High Energy Physics::Experiment ,Rapidity ,Nuclear Experiment ,010306 general physics ,Engineering (miscellaneous) - Abstract
The inclusive cross section for the photoproduction of neutral pions has been measured as a function of the transverse momentum, rapidity, and Feynman x of the pizero mesons at an average photon--proton centre-of-mass energy of 208 GeV and for photon virtualities below Q^2=0.01 GeV^2. The pizero measurement extends the range covered by previous charged particle measurements at HERA by two units of rapidity in the photon direction down to a value of -5.5 in the gamma p centre-of-mass frame. The pizero transverse momentum distribution is well described over the whole measured range by a power law ansatz, while an exponential fit falls below the data at transverse momentum values above 1.5 GeV/c. Good agreement with the predictions of the Monte Carlo models PYTHIA and PHOJET is found. In the context of the PYTHIA model the data are inconsistent with large intrinsic transverse momentum values in the photon., 20 pages, 6 figures and 3 tables
- Published
- 2000