Related papers: Photon Structure
We present results from NLO QCD calculations on the production of jets in ep collisions at HERA in a continuous range of photon virtuality Q^2. Special attention is given to the collinear singularities from the virtual photon and the…
Some selected topics in photoproduction are reviewed. In particular, the focus is on quasi-real photon-proton scattering as measured at HERA. Single & dijet rates and jet profiles are discussed, as are open charm production and inelastic…
The parton momentum densities in the proton are obtained from a NLO QCD analysis of structure functions measured by HERA and fixed target experiments. The uncertainties in these parton densities, the structure functions and related cross…
In this contribution we discuss recent measurements by the LEP experiments on photon structure functions.
The measurement of the proton structure function at HERA is often seen as a hint for the observation of saturation in high-energy QCD e.g. through the observation of geometric scaling. Accordingly, the dipole picture provides a powerful…
We present results of calculations of the total and jet photoproduction cross sections at HERA and Fermilab energies$^1$. The calculations take into account the high-energy QCD structure of the photon and are performed for different photon…
The production of a hard and isolated photon accompanied by one or two jets in large-Q2 deep inelastic ep scattering is calculated at next-to-leading order. We include consistently contributions from quark-to-photon fragmentation and study…
Recent experimental results on the partonic structure of the photon and on the color singlet exchange in strong interaction processes are reviewed. At the LEP electron-positron and HERA lepton-proton colliders, complementary and consistent…
Attention is paid to recent results from the ZEUS Collaboration on the photo- and electro- production of leading neutrons in e^+ p collisions at HERA. Some implications for the structure of the pion and the nucleon are discussed.
The first measurements of the diffractive structure function $F_2^{D(3)}$ at HERA are discussed. A factorisable interpretation in which a partonic structure is assigned to the pomeron is investigated through QCD analyses in which both the…
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…
Properties of the hadronic final state in photoproduction events with large transverse energy are studied at the electron-proton collider HERA. Distributions of the transverse energy, jets and underlying event energy are compared to…
The LEP experiments are making real progress in understanding the structure of the photon, though the results do not yet give such clear demonstrations of QCD in action as the proton structure has done. Other new results are reported,…
We discuss the inclusive jet production at HERA in the next-to-leading logarithm approximation. Theoretical uncertainties are considered in some details. We show the importance of the jet rapidity distribution to constrain the parton…
A brief survey is given of recent HERA results in jet production and prompt photon production, together with the evaluation of the QCD coupling constant alpha_s.
Experimental results on beauty production at HERA are reviewed in the context of similar measurements at other colliders. As a result of a phenomenological study of the QCD scale dependence of many different NLO and NNLO predictions, a…
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…
The production of prompt photons is measured in the photoproduction regime of electron-proton scattering at HERA. The analysis is based on a data sample corresponding to a total integrated luminosity of 340 pb^-1 collected by the H1…
The next-to-leading order (NLO) QCD calculation for the isolated photon and isolated photon plus jet photoproduction at the ep collider DESY HERA is presented. The predictions for the isolated photon with no restrictions imposed on the jet…
Interactions of virtual photons are analyzed in terms of their parton distribution functions. It is shown that the concept of parton distribution functions is phenomenologically very useful even for highly virtual photonds involved in hard…