Leading neutron energy and pT distributions in deep inelastic scattering and photoproduction at HERA
Nuclear Physics B 776:1-2 (2007) 1-37
Authors:
S Chekanov, M Derrick, S Magill, S Miglioranzi, B Musgrave, D Nicholass, J Repond, R Yoshida, MCK Mattingly, M Jechow, N Pavel, AG Yag眉es Molina, S Antonelli, P Antonioli, G Bari, M Basile, L Bellagamba, M Bindi, D Boscherini, A Bruni, G Bruni, L Cifarelli, F Cindolo, A Contin, M Corradi, S De Pasquale, G Iacobucci, A Margotti, R Nania, A Polini, L Rinaldi, G Sartorelli, A Zichichi, D Bartsch, I Brock, S Goers, H Hartmann, E Hilger, HP Jakob, M J眉ngst, OM Kind, E Paul, R Renner, U Samson, V Sch枚nberg, R Shehzadi, M Wlasenko, NH Brook, GP Heath, JD Morris, T Namsoo, M Capua, S Fazio, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, KJ Ma, ZA Ibrahim, B Kamaluddin, WAT Wan Abdullah, Y Ning, Z Ren, F Sciulli, J Chwastowski, A Eskreys, J Figiel, A Galas, M Gil, K Olkiewicz, P Stopa, L Zawiejski, L Adamczyk, T Bo艂d, I Grabowska-Bo艂d, D Kisielewska, J 艁ukasik, M Przybycie艅, L Suszycki, A Kota艅ski, W S艂omi艅ski, V Adler, U Behrens, I Bloch, C Blohm, A Bonato, K Borras, N Coppola, A Dossanov, J Fourletova, A Geiser, D Gladkov, P G枚ttlicher, I Gregor, T Haas, W Hain, C Horn, B Kahle, U Klein
Abstract:
The production of energetic neutrons in ep collisions has been studied with the ZEUS detector at HERA. The neutron energy and pT2 distributions were measured with a forward neutron calorimeter and tracker in a 40 聽 pb-1 sample of inclusive deep inelastic scattering (DIS) data and a 6 聽 pb-1 sample of photoproduction data. The neutron yield in photoproduction is suppressed relative to DIS for the lower neutron energies and the neutrons have a steeper pT2 distribution, consistent with the expectation from absorption models. The distributions are compared to HERA measurements of leading protons. The neutron energy and transverse-momentum distributions in DIS are compared to Monte Carlo simulations and to the predictions of particle exchange models. Models of pion exchange incorporating absorption and additional secondary meson exchanges give a good description of the data. 漏 2007 Elsevier B.V. All rights reserved.
