Related papers: Theoretical Aspects of HERA Physics
This article provides a review of progress made in understanding inverse power law corrections 1/Q^p where Q is the hard scale for a given QCD observable. Special emphasis is given to comparisons of theory with HERA results.
The HERA data at large $Q^2$ and small-$x$ investigate large distances on the light-cone. At such large distances the scattered quarks can maintain their colour identity by polarizing the vacuum as they transfer energy to it. We calculate…
We computed the static potential and Wilson loops to $O(\alpha^2)$ in perturbation theory for different lattice quark and gluon actions. In general, we find short distance lattice data to be well described by ``boosted perturbation…
QCD coherence effects in initial state radiation at small x in deep inelastic scattering in HERA kinematics are studied with the help of the Monte Carlo model SMALLX. Theoretical assumptions based on the CCFM evolution equation are reviewed…
Exploration of the small $x$ kinematic region by the HERA experiments led to a revival of some models which existed before the advent of Quantum Chromo Dynamics (QCD) as the theory of the strong interactions. Predictions of these models for…
We review small $x$ contributions to perturbative evolution equations for parton distributions, and their resummation. We emphasize in particular the resummation technique recently developed in order to deal with the apparent instability of…
We review how experimental data collected at the HERA lepton-hadron collider have improved our theoretical and phenomenological understanding of the standard model, and specifically of its QCD sector.
Disentangle the hard and soft dynamics in diffractive DIS is one of the main open questions of the strong interactions. We propose the study of the logarithmic slope in $Q^2$ of the diffractive structure function as a potential observable…
In this talk we review recent perturbative and non-perturbative developments in Heavy Quark Effective Theory (HQET).
This talk is the second part of the summary of the theory section at DIS'97. We demonstrated that theory of the "hard" processes, based on QCD, has achieved a better understanding of available experimental data during the past year. This…
The excess in high-Q^2 events at HERA is introduced and possible explanations within the framework of R-parity violating supersymmetry are discussed.
We give a brief account of some physics topics which could be addressed at a collider consisting of the HERA proton ring and the future e+e- Linear Collider. A few experimental aspects are also discussed.
A review is presented of the different theoretical models proposed to approach consistently the interplay between soft and hard physics, that can now be studied experimentally at HERA for the first time.
A detailed comparison of HERA data at low Bjorken-$x$ and low four-momentum-transfer squared, $Q^2$, with predictions based on $\ln{Q^2}$ evolution (DGLAP) in perturbative Quantum Chromo Dynamics suggests inadequacies of this framework. The…
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…
We discuss the perturbative QCD description of diffractive deep-inelastic scattering, and extract diffractive parton distributions from recent HERA data. The asymptotic collinear factorisation theorem has important modifications in the…
Even today, the convergence of the decay widths and some of the Dalitz plot parameters of the $\eta $$\,\rightarrow $$3\pi$ decays seems problematic in low energy QCD. We provide an overview of the current experimental and theoretical…
Recent HERA data on structure functions and reduced cross-sections are presented and their significance for our understanding of the low-x region is discussed.
We review the theoretical framework of jet photoproduction at HERA discussing the conceptual ideas, phenomenological models, and higher order perturbative calculations. Numerically, we study the physically interesting distribution of…
Hadronic diffraction has become a hot and fashionable subject in recent years due to the great interest triggered by the HERA and Tevatron data. These data have helped to put the field in a different perspective paving the road to a…