Related papers: Are valence quarks rotating?
The production of hadrons in polarized lepton-nucleon deep inelastic scattering is discussed. The helicity density matrix of the hadron is computed within the QCD hard scattering formalism and its elements are shown to yield information on…
We discuss the Wigner functions of the nucleon which provide multi-dimensional images of the quark distributions in phase space. They combine in a single picture all the information contained in the generalized parton distributions (GPDs)…
The proton spin budget is discussed. Results are presented from inclusive and semi-inclusive deep inelastic scattering and from deeply virtual Compton scattering. They permit interpretations towards the determination of various…
We consider deeply virtual Compton scattering and deep inelastic scattering in presence of Regge exchanges that are part of the non-perturbative quark-nucleon amplitude. In particular we discuss contribution from the Pomeron exchange and…
We investigate the indirect effects of heavy vector bileptons being exchanged in polarized Moller scattering, at the next generation of linear colliders. Considering both longitudinal and transverse beam polarization, and accounting for…
We investigate the transverse quark spin densities of the nucleon with the lowest moment within the framework of the SU(3) chiral quark-soliton model, emphasizing the strange quark spin density. Based on previous results of the vector and…
Quark orbital angular momentum in the proton is evaluated via a Lattice QCD calculation of the second Mellin moment of the twist-3 generalized parton distribution $\widetilde{E}_{2T} $ in the forward limit. The connection between this…
We study both polarized and unpolarized proton structure functions in the kinematical region of large Bjorken x and four-momentum transfer of few GeV^2. In this region the phenomenon of parton-hadron duality takes place between the smooth…
The possibility to extract the quark transverse-momentum distributions in the neutron from semi-inclusive deep inelastic electron scattering off polarized 3He is illustrated through an impulse approximation analysis in the Bjorken limit.…
A review on the theoretical aspects and the experimental results of polarized deep inelastic scattering and of other hard scattering processes is presented. The following items are discussed: longitudinally polarized structure functions,…
Deep inelastic electron-proton scattering is analyzed in the target rest frame using a theoretical approach suitable to describe many-body systems of {\em bound} constituents subject to {\em interactions}. At large three-momentum transfer…
I review recent theoretical results on polarized deep inelastic lepton nucleon scattering. Some specific issues, like $Q^2$ evolution of structure functions, the small $x$ behaviour, and the determination of polarized parton densities, are…
We argue that due to parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions -- the generalized transverse momentum distributions -- that describes the configuration of an…
We explore the opportunities of using electron scattering by screened Coulomb potential as a tool to retrieve properties of the relativistic vortex beams of electrons, such as their transverse momentum and orbital angular momentum (OAM). We…
For the omega-hyperon passing through matter the phenomena of spin rotation and oscillation has investigated quantitatively. Connection of these phenomena with constituent quark rescattering has been determined. It allows one to investigate…
We propose a unified new approach to describe polarized and unpolarized quark distributions in the proton based on the gauge-gravity correspondence, light-front holography, and the generalized Veneziano model. We find that the…
Owing to recent advances in laser technology, it has become important to investigate fundamental laser-assisted processes in very powerful laser fields. In the present work and within the framework of laser-assisted quantum electrodynamics…
We study the contribution of diffractive $Q \bar Q$ production to the $F_2^D$ proton structure function and the longitudinal double-spin asymmetry in polarized deep--inelastic $lp$ scattering. We show the strong dependence of the $F_2^D$…
The coplete analysis of the model-independent leading radiative corrections to cross-section and polarization observables in semi-inclusive deep-inelastic electron-nucleus scattering with detection of a proton and scattered electron in…
Inclusive and semi-inclusive deep inelastic leptoproduction offers possibilities to study details of the quark and gluon structure of the hadrons involved. In many of these experiments polarization is an essential ingredient. We also…