Related papers: Real and Virtual Photon Structure
The production of jets is studied in collisions of virtual photons, gamma*-p and gamma*-gamma*, specifically for applications at HERA and LEP2. Photon flux factors are convoluted with matrix elements involving either direct or resolved…
The production of jets is studied in collisions of virtual photons, gamma*-p and gamma*-gamma*, specifically for applications at HERA and LEP2. Photon flux factors are convoluted with matrix elements involving either direct or resolved…
The structure of the photon is probed in photon-photon interactions at LEP and in photon-proton interactions at HERA.
Some aspects of extracting the information on the structure of virtual photons from jet production in ep and e^+e^- collisions are discussed.
We point out that in processes involving the parton content of the photon the usual effective photon approximation should be modified. The reason is that the parton content of virtual photons is logarithmically suppressed compared to real…
The measurement of forward jet cross sections has been suggested as a promising probe of new small x parton dynamics and the question is whether the new HERA data provide an indication of this. In this paper the influence of resolved photon…
Development of concepts related to the photon and its high energy hadronic interaction is briefly reviewed. A photon considered as an ideal probe of hadron structure, paradoxically is also considered as an ideal target to test the…
The status of measurements and interpretation of the proton structure function F2 is summarized. The measurements are subjected to DGLAP fits, from which the gluon density is extracted and a comparison to measurements of F2c is performed.…
Preliminary results are presented from a study of dijet photoproduction in ep collisions with both virtual and quasi-real photons at the ZEUS detector. Samples of events with photons of virtuality $P^2$ in the ranges $0.1 < P^2 < 0.55$…
The sensitivity of the Deep Inelastic Compton (DIC) scattering at HERA to the structure of the virtual photon is discussed. It is demonstrated that the gluonic content of the virtual photon can be pinned down by measuring the photons with…
Jet production in electron-proton collisions at HERA provides a unique testing ground for Quantum Chromodynamics (QCD). Apart from the determination of the strong coupling constant $\alpha_s$, ep jet data may especially be used to gain…
The present knowledge of the structure of the photon is presented with emphasis on measurements of the photon structure obtained from deep inelastic electron-photon scattering at e+e- colliders. This review covers the leptonic and hadronic…
The QCD treatment of the parton structure of virtual photons is briefly recalled, and possible limitations and open questions are pointed out. Various models for these densities are compared, completed by a short discussion of the treatment…
Deeply Virtual Compton Scattering (DVCS) in $ep$ collisions has emerged in recent years as a an essential reaction to obtain information on the correlation of partons in the hadron (proton) or on the transverse distribution of these…
Standard parton distribution functions contain neither information on the correlations between partons nor on their transverse motion, then a vital knowledge about the three dimensional structure of the nucleon is lost. Hard exclusive…
Prompt photons, together with an accompanying jet, have been studied in the photoproduction regime of ep scattering with the ZEUS detector at HERA. Predictions based on leading-logarithm parton-shower Monte Carlo models and…
The precision of new HERA data on jet photoproduction opens up the possibility to discriminate between different models of the photon structure. This requires equally precise theoretical predictions from perturbative QCD calculations. In…
This is the first of two papers in which we study real and virtual photon-proton scattering in a nonperturbative framework. We classify different contributions to this process and identify the leading contributions at high energies. We then…
The discussion on the production of prompt photons with pT of a few GeV in the tagged process ep -> e gamma X with small Q^2 (DIC process) at the HERA collider is presented. Photons produced in the forward (proton) direction are mainly…
The dependence of dijet production on the virtuality of the exchanged photon, Q^2, has been studied by measuring dijet cross sections in the range 0 < Q^2 < 2000 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 38.6…