Related papers: The colour dipole approach to small-x processes
In the high-energy limit, perturbative calculations in QCD are conveniently done using the dipole picture which factorizes the scattering amplitude into a perturbative part and the nonperturbative scattering off the nuclear target,…
Using a combination of S-Matrix and perturbative QCD properties in the small x_{Bjorken} regime, we propose a formulation of hard diffraction unifying the partonic (Ingelman-Schlein) Pomeron, Soft Colour Interaction and QCD dipole…
The ratio of the cross sections for the transversely and longitudinally virtual photon polarizations, $\sigma^{\gamma^{*}p}_{L/T}$, at high photon-hadron energy scattering is studied. I investigate the relationship between the gluon…
We present the first evaluation of the color dipole diffraction slope from the data on diffractive photo- and electroproduction of vector mesons. The energy and dipole size dependence of the found dipole diffraction slope are consistent…
We study the DVCS amplitude within the color dipole approach. The light-cone wave function of a real photon is evaluated in the instanton vacuum model. Our parameter free calculations are able to describe H1 data, both the absolute values…
Using the high energy color dipole approach, we study the exclusive photoproduction of lepton pairs. We use simple models for the elementary dipole-hadron scattering amplitude that captures main features of the dependence on atomic number…
We use data on the deep inelastic structure function F_2 in order to constrain the cross-section for scattering a colour dipole off a proton. The data seem to prefer parameterisations which include saturation effects. That is they indicate…
We analyze the process of two-particle scattering with unstable particle in an intermediate state. It was shown that the cross-section can be represented in the universal factorized form for an arbitrary set of particles. Phenomenological…
This program can be used to simulate polarised nucleon - nucleon collisions at high energies. Spins of colliding particles are taken into account. The program allows to calculate cross sections for various processes.
Polarization phenomena are essential for the understanding of elementary processes, and are typically large in the threshold region. The selection rules with respect to P-parity, angular momentum, isotopic spin and the Pauli principle allow…
When approximating a function that depends on a parameter, one encounters many practical examples where linear interpolation or linear approximation with respect to the parameters prove ineffective. This is particularly true for responses…
Recent theoretical developments to calculate cross sections of hadronic objects in the high energy limit are summarised and experimental attempts to establish the need for new QCD effects connected with a resummation of small hadron…
Interactions of high-energy neutrinos with matter can be studied through the angular separation observed in dimuon production, an observable particularly sensitive to the transverse momentum dynamics of partons. In this work, we develop a…
A partial wave analysis is presented of data on photoproduction of hyperons including single and double polarization observables. The large spin transfer probability reported by the CLAS collaboration can be successfully described with an…
Small-x DIS is described as the scattering of a partonic fluctuation of the photon off a superposition of target color fields. Diffraction occurs if the emerging partonic state is in a color singlet. Introducing a specific model for the…
In the paper the extension of the Geometrical Two-Chain model to higher energies is presented. The agreement with experimental data is achieved using pre-hadronization chain breakups due to coloured dipole radiation mechanism and the…
Dipole and higher moments are physical quantities used to describe a charge distribution. In analogy with electromagnetism, it is possible to define the dipole moments for a gray-scale image, according to the single aspect of a gray-tone…
When studying the production of minijets and transverse energy flow in high energy hadron-hadron or nucleus-nucleus collisions, two essential points have to be taken into account. First, one has to account for the virtuality of the…
We describe diffractive hard processes in the framework of QCD factorization and discuss what one can learn from the study of hadronic systems with small transverse size.
We reproduce the DIS measurements of the proton structure function at high energy from the dipole model in momentum space. To model the dipole-proton forward scattering amplitude, we use the knowledge of asymptotic solutions of the…