Related papers: Generalized Vector Dominance and Low-x Proton Stru…
An attempt is made to illustrate the relation between low x process es and diffraction. ep scattering provides a unique laboratory, a single hadronic target probed by a point like lepton, where one can try to understand diffraction in terms…
The structure of the virtual photon and its contribution to small x processes in deep inelastic scattering at HERA is discussed.
In deep-inelastic positron-proton scattering, the lepton-jet azimuthal angular asymmetry is measured using data collected with the H1 detector at HERA. When the average transverse momentum of the lepton-jet system, $\lvert \vec{P}_\perp…
Data from H1 and ZEUS on the structure and the quark and gluon densities of the proton are discussed. A brief excursion is made into the field of inclusive diffraction by deep inelastic scattering. The comparison of e- p and e+ p scattering…
Helicity-dependent generalized parton distributions of the nucleon are derived from the overlap representation of generalized parton distributions using light-cone wave functions obtained in constituent quark models. Results from two…
Experimental results obtained with the HERA collider and recent progress in their theoretical interpretation are reviewed. After a short introduction to HERA physics, deep inelastic scattering and photoproduction are discussed as (virtual)…
The generalized parton distributions are non-perturbative objects, which encode information on long distance dynamics in a number of exclusive processes. They are hybrids of conventional parton densities, distribution amplitudes and hadron…
An explicit model for the proton structure function interpolating between low- (VMD and Regge behavior)and high-$Q^2$ (GLAP evolution) is suggested. The model is fitted to the experimental data in a wide range of the kinematical variables…
We present an introductory discussion of deep-inelastic lepton-proton scattering as a means to probe the substructure of the proton. A resume of QCD is given, emphasizing the running of the coupling constant and the DGLAP evolution…
We provide a formulation of generalised vector dominance (GVD) for low-x deep-inelastic scattering that explicitly incorporates the ${\gamma}^{\ast} \to q{\bar q}$ transition and a QCD-inspired ansatz for the $(q{\bar q})p$…
The contribution of both inclusive and exclusive cross-section data from HERA to our knowledge of parton distribution functions is reviewed and future prospects are outlined.
Recent HERA data on small-x structure functions as well as DIS diffraction and diffractive vector meson production are presented. The relationship between these processes and possible indications of dynamics beyond the DGLAP formalism are…
Data from the HERA collider experiments, H1 and ZEUS, have been fundamental to the rapid recent development of our understanding of the partonic composition of the proton and of QCD. This report focuses on inclusive measurements of neutral…
The subject of lepton-hadron scattering is discussed from its earliest beginnings, concentrating on what we have learnt from the HERA electron-proton storage ring. A brief selection of the HERA I results most relevant to LHC are discussed.…
A review is presented of numerous recent results, particularly those submitted to the EPS-HEP99 conference: very high Q^2 ep interactions and direct tests of the Standard Model, new measurements of the structure of the proton (including…
The elastic production of vector mesons at HERA is discussed from the theoretical point of view. We briefly review different models, their successes and shortcomings. Main emphasis is put on recent issues in perturbative QCD calculations.…
Longitudinal polarisation of the lepton beam is a key ingredient to the success of the world's unique e\pmp ring collider HERA. This article aims at providing a brief introduction to the physics motivation for deep-inelastic scattering of…
The $e^{+}p$ and $e^{-}p$ scattering data recorded at HERA during the recent years offer the possibility to study electroweak effects in $ep$ interactions apparent at high momentum transfers, $Q^{2}$, and to reveal information on the proton…
We briefly summarize the equivalence of off-diagonal generalized vector dominance and the colour-dipole approach to deep-inelastic scattering (DIS) in the diffraction region of values of $x \simeq Q^2/W^2 << 1$.
Recent jet physics results from ep and $\gamma$p scattering at HERA will be reviewed covering cross-section measurements, the extraction of QCD parameters, the transition region from photoproduction to deep-inelastic scattering and the…