Related papers: Photoproduction of jets and the virtual structure …
We investigate in detail the effect of a direct pomeron coupling to quarks on the production of jets in $ep$ scattering with almost real photons. Jet production via a direct pomeron coupling is compared with the resolved--pomeron mechanism.…
Present data on the partonic content of the photon are reviewed. The results on the unpolarized structure functions from DIS experiments and on large pt jet production processes in gamma-gamma and gamma-p collisions are discussed for both…
The production of charged hadrons and jets is measured in collisions of quasi-real photons. The data were taken with the OPAL detector at LEP at e+e- centre-of-mass energies of 161 and 172 GeV. The measured cross-sections are compared to…
The dependence of the photon structure on the photon virtuality, Q^2, is studied by measuring the reaction e^+p\to e^+ + {\rm jet} + {\rm jet} + {\rm X} at photon-proton centre-of-mass energies 134 < W < 223 GeV. Events have been selected…
A new next-to-leading order Monte Carlo program for the calculation of fully differential jet cross sections in photoproduction is described. The contributions from both resolved and direct components are included. A comparison between the…
Recent results from the H1 and ZEUS collaborations on hard QCD processes in ep interactions are reviewed. The topics cover jet shapes, the structure of real and virtual photons, and the production of J/Psi mesons and open charm.
Di-jet and inclusive charged hadron production cross-sections measured in photon-photon collisions by OPAL are compared to NLO pQCD calculations. Jet shapes measured in photon-photon scattering by OPAL, in deep-inelastic ep scattering by H1…
We study jet production in photon-photon reactions at the next-to-leading logarithm accuracy. Special emphasis is placed on the discussion of the theoretical uncertainties and on the role of the hadronic component of the photon structure…
In peripheral relativistic heavy ion collisions at the Large Hadron Collider, jet+jet and photon+jet final states can be produced when a photon from the virtual photon field surrounding the nucleus interacts with a parton in the opposite…
We present next-to-leading order QCD predictions for single-inclusive and di-jet observables, relevant to the collisions of two on-shell photons, obtained with a recently completed computation based upon the subtraction method. We compare…
Measurements sensitive to the structure of both real and virtual photons are presented and compared to theoretical models with various photon parton distribution functions (PDFs). Measurements for real photons show a tendency for the…
The photoproduction of isolated photons, both inclusive and together with a jet, has been measured with the ZEUS detector at HERA using an integrated luminosity of $374\, \mathrm{pb}^{-1}$. Differential cross sections are presented in the…
Interactions of virtual photons are analyzed in terms of photon structure. It is argued that the concept of parton distribution functions is phenomenologically very useful even for highly virtual photons involved in hard collisions. This…
The photoproduction of dijet events, where the two jets with the highest transverse energy are separated by a large gap in pseudorapidity, have been studied with the ZEUS detector using an integrated luminosity of 39 pb$^{-1}$. Rapidity-gap…
Measurements of the structure of the virtual photon in the transition region between quasi-real photons and those far from mass-shell have been made with the ZEUS detector at HERA, using an integrated luminosity of 38pb-1. Dijet final…
Recent results from ZEUS for inclusive jet cross sections, dijet cross sections and dijet angular distributions are compared with NLO perturbative QCD calculations. The observation of isolated high $P_T$ photons (prompt photons) is also…
Present data on the partonic content of the photon from LEP, TRISTAN and HERA accelerators are reviewed and the essential aspects of the underlying ideas and methods are pointed out. Results of the unpolarized photon structure function F_2…
The dijet cross section as a function of both the fraction of the photon momentum participating in the hard process, x_\gamma^{OBS}, and the photon's virtuality, Q^2, is compared with the predictions of Herwig 5.9 for various photon parton…
The process of exclusive vector meson production (gamma gamma to J/psi rho^0) is studied for almost real photons. This process may be reduced to photoproduction of J/psi off the rho^0 meson. We discuss the possibility of extracting the…
The photoproduction of beauty quarks in events with two jets and a muon has been measured with the ZEUS detector at HERA using an integrated luminosity of 110 pb$^{- 1}$. The fraction of jets containing b quarks was extracted from the…