Forward jet production in deep inelastic scattering at HERA
European Physical Journal C 6:2 (1999) 239-252
Abstract:
The inclusive forward jet cross section in deep inelastic e+p scattering has been measured in the region of cursive Greek chi-Bjorken, 4.5 · 10-4 to 4.5 · 10-2. This measurement is motivated by the search for effects of BFKL-like parton shower evolution. The cross section at hadron level as a function of cursive Greek chi is compared to cross sections predicted by various Monte Carlo models. An excess of forward jet production at small cursive Greek chi is observed, which is not reproduced by models based on DGLAP parton shower evolution. The Colour Dipole model describes the data reasonably well. Predictions of perturbative QCD calculations at the parton level based on BFKL and DGLAP parton evolution are discussed in the context of this measurement.Inclusive jet cross section in p̄p collisions at √ = 1.8 TeV
Physical Review Letters 82:12 (1999) 2451-2456
Abstract:
We have made a precise measurement of the central inclusive jet cross section at √s = 1.8 TeV. The measurement is based on an integrated luminosity of 92pb-1 collected at the Fermilab Tevatron p̄p Collider with the D0 detector. The cross section, reported as a function of jet transverse energy (ET ≥ 60 GeV) in the pseudorapidity interval |±| ≤ 0.5, is in good agreement with predictions from next-to-leading order quantum chromodynamics. © 1999 The American Physical Society.Measurement of dijet photoproduction at high transverse energies at HERA
European Physical Journal C 11:1 (1999) 35-50
Abstract:
The cross section for dijet photoproduction at high transverse energies is presented as a function of the transverse energies and the pseudorapidities of the jets. The measurement is performed using a sample of ep-interactions corresponding to an integrated luminosity of 6.3 pb-1, recorded by the ZEUS detector. Jets are defined by applying a kT-clustering algorithm to the hadrons observed in the final state. The measured cross sections are compared to next-to-leading order QCD calculations. In a kinematic regime where theoretical uncertainties are expected to be small, the measured cross sections are higher than these calculations.Measurement of high-Q2 neutral-current e+p deep inelastic scattering cross-sections at HERA
European Physical Journal C 11:3 (1999) 427-445
Abstract:
The e+p neutral-current deep inelastic scattering differential cross-sections dσ/dQ2, for Q2 > 400 GeV2, dσ/dx and dσ/dy, for Q2 > 400, 2500 and 10000 GeV2, have been measured with the ZEUS detector at HERA. The data sample of 47.7 pb-1 was collected at a center-of-mass energy of 300 GeV. The cross-section, dσ/dQ2, falls by six orders of magnitude between Q2 = 400 and 40000 GeV2. The predictions of the Standard Model are in very good agreement with the data. Complementing the observations of time-like Z° contributions to fermion-antifermion annihilation, the data provide direct evidence for the presence of Z° exchange in the space-like region explored by deep inelastic scattering.Measurement of inclusive D*± and associated dijet cross sections in photoproduction at HERA
European Physical Journal C 6:1 (1999) 67-83