51猎奇入口 of deep inelastic inclusive and diffractive scattering with the ZEUS forward plug calorimeter
Nuclear Physics B 713:1-3 (2005) 3-80
Authors:
S Chekanov, M Derrick, S Magill, S Miglioranzi, B Musgrave, J Repond, R Yoshida, MCK Mattingly, N Pavel, AG Yag眉es Molina, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, L Cifarelli, F Cindolo, A Contin, M Corradi, S De Pasquale, P Giusti, G Iacobucci, A Margotti, A Montanari, R Nania, F Palmonari, A Pesci, A Polini, L Rinaldi, G Sartorelli, A Zichici, G Aghuzumtsyan, D Bartsch, I Brock, S Goers, H Hartmann, E Hilger, P Irrgang, HP Jakob, O Kind, U Meyer, E Paul, J Rautenberg, R Renner, KC Voss, M Wang, M Wlasenko, DS Bailey, NH Brook, JE Cole, GP Heath, T Namsoo, S Robins, M Capua, A Mastroberardino, M Schioppa, G Susinno, E Tassi, JY Kim, KJ Ma, M Helbich, Y Ning, Z Ren, WB Schmidke, F Sciulli, J Chwastowski, A Eksreys, J Figiel, A Galas, K Olkiewicz, P Stopa, D Szuba, L Zawiejski, L Adamczyk, T Bo艂d, I Grabowska-Bo艂d, D Kisielewska, AM Kowal, J 艁ukasik, M Przybycie艅, L Suszycki, J Szuba, A Kota艅ski, W S艂omi艅ski, V Adler, U Behrens, I Bloch, K Borras, DG Cassel, G Drews, J Fourletova, A Geiser, D Gladkov, F Goebel, P G枚ttlicher, R Graciani Diaz, O Gutsche
Abstract:
Deep inelastic scattering and its diffractive component, ep 鈫� e鈥� 纬* p 鈫� e鈥� X N, have been studied at HERA with the ZEUS detector using an integrated luminosity of 4.2 pb-1. The measurement covers a wide range in the 纬* p c.m. energy W (37-245 GeV), photon virtuality Q2 (2.2-80 GeV2) and mass MX (0.28-35 GeV). The diffractive cross section for MX > 2 GeV rises strongly with W; the rise is steeper with increasing Q2. The latter observation excludes the description of diffractive deep inelastic scattering in terms of the exchange of a single pomeron. The ratio of diffractive to total cross section is constant as a function of W, in contradiction to the expectation of Regge phenomenology combined with a naive extension of the optical theorem to 纬* p scattering. Above MX of 8 GeV, the ratio is flat with Q2, indicating a leading-twist behaviour of the diffractive cross section. The data are also presented in terms of the diffractive structure function, F2D(3)(尾, x鈩�, Q2), of the proton. For fixed 尾, the Q2 dependence of x鈩�F2 D(3) changes with x鈩� in violation of Regge factorisation. For fixed x鈩�, x鈩� F2D(3) rises as 尾 鈫� 0, the rise accelerating with increasing Q2. These positive scaling violations suggest substantial contributions of perturbative effects in the diffractive DIS cross section. 漏 2005 Elsevier B.V. All rights reserved.