Measurement of High-Q Neutral-Current ep Deep Inelastic Scattering Cross-Sections at HERA

The ep neutral-current deep inelastic scattering differential cross-sections dσ/dQ, for Q > 400 GeV, dσ/dx and dσ/dy, for Q > 400, 2500 and 10000 GeV, have been measured with the ZEUS detector at HERA. The data sample of 47.7 pb was collected at a center-ofmass energy of 300 GeV. The cross-section, dσ/dQ, falls by six orders of magnitude between Q = 400 and 40000 GeV. The predictions of the Standard Model are in very good agreement with the data. Complementing the observations of time-like Z contributions to fermionantifermion annihilation, the data provide direct evidence for the presence of Z exchange in the space-like region explored by deep inelastic scattering. The ZEUS Collaboration J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida Argonne National Laboratory, Argonne, IL, USA p M.C.K. Mattingly Andrews University, Berrien Springs, MI, USA G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Pesci, A. Polini, G. Sartorelli, Y. Zamora Garcia, A. Zichichi University and INFN Bologna, Bologna, Italy f C. Amelung, A. Bornheim, I. Brock, K. Coböken, J. Crittenden, R. Deffner, M. Eckert, H. Hartmann, K. Heinloth, L. Heinz, E. Hilger, H.-P. Jakob, A. Kappes, U.F. Katz, R. Kerger, E. Paul, M. Pfeiffer, J. Rautenberg, H. Schnurbusch, A. Stifutkin, J. Tandler, A. Weber, H. Wieber Physikalisches Institut der Universität Bonn, Bonn, Germany c D.S. Bailey, O. Barret, W.N. Cottingham, B. Foster, G.P. Heath, H.F. Heath, J.D. McFall, D. Piccioni, J. Scott, R.J. Tapper H.H. Wills Physics Laboratory, University of Bristol, Bristol, U.K. o r M. Capua, A. Mastroberardino, M. Schioppa, G. Susinno Calabria University, Physics Dept.and INFN, Cosenza, Italy f H.Y. Jeoung, J.Y. Kim, J.H. Lee, I.T. Lim, K.J. Ma, M.Y. Pac Chonnam National University, Kwangju, Korea h A. Caldwell, N. Cartiglia, Z. Jing, W. Liu, B. Mellado, J.A. Parsons, S. Ritz, R. Sacchi, S. Sampson, F. Sciulli, Q. Zhu Columbia University, Nevis Labs., Irvington on Hudson, N.Y., USA q P. Borzemski, J. Chwastowski, A. Eskreys, J. Figiel, K. Klimek, K. Olkiewicz, M.B. Przybycień, L. Zawiejski Inst. of Nuclear Physics, Cracow, Poland j L. Adamczyk, B. Bednarek, K. Jeleń, D. Kisielewska, A.M. Kowal, T. Kowalski, M. Przybycień, E. Rulikowska-Zarȩbska, L. Suszycki, J. Zaja̧c Faculty of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, Cracow, Poland j Z. Duliński, A. Kotański Jagellonian Univ., Dept. of Physics, Cracow, Poland k L.A.T. Bauerdick, U. Behrens, J.K. Bienlein, C. Burgard, K. Desler, G. Drews, A. Fox-Murphy, U. Fricke, F. Goebel, P. Göttlicher, R. Graciani, T. Haas, W. Hain, G.F. Hartner, D. Hasell, K. Hebbel, K.F. Johnson, M. Kasemann, W. Koch, U. Kötz, H. Kowalski, L. Lindemann, B. Löhr, M. Mart́ınez, J. Milewski, M. Milite, T. Monteiro, M. Moritz, D. Notz, F. Pelucchi, K. Piotrzkowski, M. Rohde, P.R.B. Saull, A.A. Savin, U. Schneekloth, O. Schwarzer, F. Selonke, M. Sievers, S. Stonjek, E. Tassi, G. Wolf, U. Wollmer, C. Youngman, W. Zeuner Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany