We explore skewed parton distributions for simple, model wave-functions in a truncated two-body Fock space. Consideration of non-Gaussian wave functions is our main emphasis, from which we observe the distributions are bimodal (there can be two distinct peaks) in the Fock-space diagonal overlap region (x > ξ). We demonstrate that this behavior arises from convoluting two light-front wave functi...

The feasibility of measuring parton distribution functions of of virtual photons via the jet production at HERA is investigated. Production of jets in ep collisions at HERA offers one of the ways of studying the structure of the virtual photon. Due to the fact that this structure needs time to develop, parton distribution functions (PDF) fi(x, P , Q) of the virtual photon, probed at the hard sc...

We present a method to match the multi-parton states generated by the High Energy Jets Monte Carlo with parton showers generated by the ARIADNE program using the colour dipole model. The High Energy Jets program already includes a full resummation of soft divergences. Hence, in the matching it is important that the corresponding divergences in the parton shower are subtracted, keeping only the ...

KATIE is a parton-level event generator for hadron scattering processes that can deal with partonic initial-state momenta with an explicit transverse momentum dependence causing them to be space-like. Provided with the necessary transverse momentum dependent parton density functions, it calculates the tree-level off-shell matrix elements and performs the phase space importance sampling to produ...

The scale factor σeff , which characterizes double parton collisions in high energy hadron interactions, is a direct manifestation of the distribution of the interacting partons in transverse space, in such a way that different distributions give rise to different values of σeff in different double parton collision processes. We work out the value of the scale factor in a few reactions of inter...

Recent measurements for F2(x, Q ) have been analyzed in terms of the ‘dynamical’ and ‘standard’ parton model approach at NLO and NNLO of perturbative QCD. Having fixed the relevant NLO and NNLO parton distributions, the implications and predictions for the longitudinal structure function FL(x,Q ) are presented. It is shown that the previously noted extreme perturbative NNLO/NLO instability of F...

Deep inelastic structure functions F A 2 (x) are investigated in a Q 2 rescaling model with parton recombination effects. We find that the model can explain experimentally measured F A 2 (x) structure functions reasonably well in the wide Bjorken−x range (0.005 < x < 0.8). In the very small x region (x < 0.02), recombination results are very sensitive to input sea-quark and gluon distributions.

The time-evolution of jets in hadronic e+e− events at LEP is investigated in both positionand momentum-space, with emphasis on effects due to color flow and particle correlations. We address dynamical aspects of the four simultanously-evolving, cross-talking parton cascades that appear in the reaction e+e− → γ∗/Z0 → W+W− → q1q̄2q3q̄4, and compare with the familiar two-parton cascades in e+e− → Z0...

We give a partonic interpretation for the deeply virtual Compton scattering (DVCS) measurements of the H1 and ZEUS collaborations in the small-xB region in terms of generalized parton distributions. Thereby we have a closer look at the skewness effect, parameterization of the t-dependence, revealing the chromomagnetic pomeron, and at a model dependent access to the anomalous gravitomagnetic mom...

Operator definitions of diffractive parton distribution functions are given. A distinction is made between the special case of “Regge factorization” to the general case of “diffractive factorization” with explicit expressions for F diff 2 (βxIP , Q ;xIP , t) in both cases. A calculation from a simple field theory model is presented in the style of “constituent counting rules” for the behavior o...