ZEUS results on the measurement and phenomenology of F2 at low x and low Q2
EUROPEAN PHYSICAL JOURNAL C 7:4 (1999) 609-630
Measurement of three-jet distributions in photoproduction at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 443:1-4 (1998) 394-408
Abstract:
The cross section for the photoproduction of events containing three jets with a three-jet invariant mass of M31 > 50 GeV has been measured with the ZEUS detector at HERA. The three-jet angular distributions are inconsistent with a uniform population of the available phase space but are well described by parton shower models and script O sign(α α2s) pQCD calculations. Comparisons with the parton shower model indicate a strong contribution from initial state radiation as well as a sensitivity to the effects of colour coherence. © 1998 Elsevier Science B.V. All rights reserved.Measurement of elastic Υ photoproduction at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 437:3-4 (1998) 432-444
Abstract:
The photoproduction reaction γp → μ+ μ-p has been studied in ep interactions using the ZEUS detector at HERA. The data sample corresponds to an integrated luminosity of 43.2pb-1. The Υ meson has been observed in photoproduction for the first time. The sum of the products of the elastic Υ(1S), Υ(2S),Υ(3S) photoproduction cross sections with their respective branching ratios is determined to be 13.3 ± 6.0(stat.)-2.3+2.7(syst.) pb at a mean photon-proton centre of mass energy of 120 GeV. The cross section is above the prediction of a perturbative QCD model. © 1998 Elsevier Science B.V. All rights reserved.Search for selectron and squark production in e+p collisions at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 434:1-2 (1998) 214-230
Abstract:
We have searched for the production of a selectron and a squark in e+p collisions at a center-of-mass energy of 300 GeV using the ZEUS detector at HERA. The selectron and squark are sought in the direct decay into the lightest neutralino in the framework of supersymmetric extensions to the Standard Model which conserve R-parity. No evidence for the production of supersymmetric particles has been found in a data sample corresponding to 46.6 pb-1 of integrated luminosity. We express upper limits on the product of the cross section times the decay branching ratios as excluded regions in the parameter space of the Minimal Supersymmetric Standard Model. © 1998 Elsevier Science B.V. All rights reserved.Event shape analysis of deep inelastic scattering events with a large rapidity gap at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 421:1-4 (1998) 368-384