Related papers: Multiple hard scattering and parton correlations i…
The recently found excess of high E$_T$ jets over current QCD predictions is attributed to gluon radiation at double scattering process inside a nucleon. The order of magnitude estimate of the cross section fits experimental findings rather…
The various motivations for improving the perturbative prediction to next-to-next-to-leading order (NNLO) for basic scattering processes in proton-(anti)proton, electron-proton and electron-positron scattering are discussed in detail.…
Simple generic expressions to compute double-parton scattering (DPS) cross sections in high-energy proton-nucleus and nucleus-nucleus collisions, as a function of the corresponding single-parton cross sections, are presented. Estimates of…
This is a review of the program we started in 1968 to understand and generalize Bjorken scaling and Feynman's parton model in a canonical quantum field theory. It is shown that the parton model proposed for deep inelastic electron…
In this work the process of elastic hadron scattering is discussed. In particular, scattering amplitudes for the various Pomeron models are compared. In addition, differential elastic cross section as a function of the scattered proton…
A new approach is proposed to describe the parity violation in the process of scattering of a polarized proton by a proton at high energies. It is shown that in the tree approximation the P-odd amplitude of proton-proton scattering is…
The comparison of positron-proton and electron-proton elastic scattering cross sections is a sensitive test for the presence of two-photon exchange contributions. Thirty years ago, positron data were considered adequate to set tight limits…
Processes such as double Drell-Yan and same-sign WW production have contributions from double parton scattering, which are not well-defined because of a delta(z_\perp=0) singularity that is generated by QCD evolution. We study the single…
A few examples of quickly developing field of double parton scattering are discussed. We present arguments that the production of two pairs of charm quark-antiquark is the golden reaction to study the double parton scattering effects. We…
Recent theoretical developments in the studies of two-photon exchange effects in elastic electron-proton scattering are reviewed. Two-photon exchange mechanism is considered a likely source of discrepancy between polarized and unpolarized…
It is shown, that the hard component of quarks distribution functions induced by instantons gives the essential contribution to hard diffractive processes. We predict large polarization effects in these processes.
We review some aspects of spin physics where QCD instantons play an important role. In particular, their large contributions in semi-inclusive deep-inelastic scattering and polarized proton on proton scattering. We also review their…
We study the phenomenon of parton-hadron duality in both polarised and unpolarised electron proton scattering using the HERMES and the Jefferson Lab data, respectively. In both cases we extend a systematic perturbative QCD based analysis to…
It is shown that the parity--violating deep--inelastic scatterings of unpolarized charged leptons on polarized protons, $\ell^{\mp} + \vec P\to \stackrel{\scriptscriptstyle(-)}{\nu_{\ell}} + X$, could provide a sensitive test for the…
Quarkonium production in proton-proton collision is interesting in profiling the partons inside the nucleon. Recently, the impact of double parton scatterings (DPSs) was suggested by experimental data of associated quarkonium production…
Results on soft and hard diffraction are briefly reviewed and placed in a QCD perspective using a parton model approach. Issues addressed include factorization, scaling properties, universality of rapidity gap formation, and unitarity.…
Double parton scattering (DPS) describes two colliding hadrons having interactions in the form of two hard processes, each initiated by a separate pair of partons. Just as for single parton scattering, the resummation of soft gluon exchange…
The relation between parton and hadron multiplicity distributions is discussed. To obtain parton multiplicity distribution we propose decomposition of the multiplicity distributions of final state hadrons. Such procedure offers hope for…
We discuss the role of two different types of diagram in the proton-proton double parton scattering (DPS) cross section - single and double perturbative splitting graphs. Using explicit calculations of simple graphs from these classes we…
Polarized Compton scattering off the proton is studied within the framework of subtracted dispersion relations for photon energies up to 300 MeV. As a guideline for forthcoming experiments, we focus the attention on the role of the proton's…