Related papers: Low-x Physics
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…
Partons are defined as the quanta in a Fock space description of a hadron. Gluon saturation is described in the Weizs\"{a}cker-Williams approximation for a large nucleus. The elements of DGLAP and BFKL evolution are given with the BFKL…
We suggest a new procedure for extrapolating the parton distributions from HERA energies to higher energies at THERA and LHC. The procedure suggested consists of two steps: first, we solve the non-linear evolution equation which includes…
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…
Hadron transverse momentum spectra are proposed as a means to probe the underlying partonic dynamics in deep inelastic scattering. The BFKL evolution equation, postulated for small Bjorken-$x$, leads to an enhanced parton emission over the…
In this contribution we briefly review the current status of the dipole models and parton saturation on the basis of results presented at the HERA-LHC workshops in the years 2006-2008. The problem of foundations of the dipole models is…
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…
Deep-inelastic scattering at small x is a new field of QCD phenomenology which HERA experiments started to explore. The data show the feature expected by the perturbative Regge asymptotics. We describe the parton picture of structure…
This article describes different approaches to investigate the behavior of parton evolution in the proton by exploiting various aspects of the hadronic final state produced in Deep Inelastic Scattering Events at HERA.
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…
I discuss small x physics and its implications at very high energies. At very high energy the density of partons becomes so large that much of the physics can be described using weak coupling methods in QCD. This may allow for a solution to…
The physics of gluon saturation and non-linear evolution at small values of parton momentum fraction x in the proton and nucleus is discussed in the context of experimental results at HERA and RHIC. The rich physics potential of low-x QCD…
Saturation at low x appears as an almost unavoidable consequence of the two-gluon exchange generic structure. Consistency of the ansatz for the vector part of the color dipole cross section with conventional evolution determines the energy…
Recent results for direct searches for physics beyond the Standard Model are reviewed. The results include Tevatron II data up to 1.2 fb-1 and HERA results up to 350 pb-1. Searches for Supersymmetry, for compositeness and for large extra…
Using QCD motivated and phenomenological considerations, we construct x- dependent polarized parton distributions, which evolve under GLAP evolution, satisfy DIS data and are within positivity constraints. Each flavor is done separately and…
Current and future experimental studies of the high-energy limit of QCD, dominated by non-linear gluon dynamics in the low-x sector of the hadron wavefunctions, are presented. Results at HERA (proton) and RHIC (nucleus) pointing to the…
In these lectures I introduce the basics of HERA physics and give a survey of the major aspects, discussing in somewhat more depth the subject of low $x$ physics.
In order to probe the dynamics of parton evolution in deep inelastic scattering at small x, high-p_T particles produced centrally in pseudorapidity are studied. In the BFKL mechanism gluon radiation is expected to be more abundant than for…
The expectations for and the measurements of transverse energy flows, single particle p_T spectra, and the rate of forward jets in deep inelastic ep events from the H1 and ZEUS experiments at HERA are reported and discussed. It is shown…
We study quantum fluctuations of the nucleon's parton densities by combining QCD factorization for hard processes with the notion of cross section fluctuations in soft diffraction. The fluctuations of the small-x gluon density are related…