Related papers: Chromodynamic Lensing and $\perp$ Single Spin Asym…
We discuss the way in which factorisation is partially maintained but nevertheless modified by process-dependent colour factors in hadronic single-spin asymmetries. We also examine QCD evolution of the twist-three gluonic-pole strength…
The special role played by singly polarized high-energy hadron-hadron collisions in Spin Physics is discussed: In such processes, the measured and the calculated quantities can be and have been directly compared with each other --- without…
We use a new set of Collins functions to update a previous prediction on the azimuthal asymmetries of pion productions in semi-inclusive deep inelastic scattering (SIDIS) process on a transversely polarized nucleon target. We find that the…
Recent developments showed that light cone parton distributions can be studied by investigating the large momentum limit of the so-called quasiparton distributions, which are defined in terms of spacelike correlators, and therefore can be…
A Fourier analysis of double-spin azimuthal asymmetries measured at HERMES in semi-inclusive deep-inelastic scattering of longitudinally polarized leptons off tranversely polarized protons is presented for pions and charged kaons. The…
We investigate the generalized parton distributions (GPDs) with non-zero $\xi$ and $\Delta^\perp$ for a relativistic spin-1/2 composite system, namely for an electron dressed with a photon, in light-front framework by expressing them in…
We analyse the role of partonic transverse motion in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes. Imposing appropriate kinematical conditions, we find some constraints which fix an upper limit to the range of…
Within the framework of light-cone quantization we derive the overlap representation of generalized parton distributions for transversely polarized quarks using the Fock-state decomposition in the transverse-spin basis. We apply this…
The production of D mesons in the scattering of transversely polarized protons off unpolarized protons at RHIC offers a clear opportunity to gain information on the Sivers gluon distribution function. D production at intermediate rapidity…
A novel spin polarization separation of reflected light is observed, when a linearly polarized Gaussian beam impinges on an air-glass interface at Brewster angle. In the far-field zone, spins of photons are oppositely polarized in two…
The connection between parton distributions as a function of the impact parameter and off-forward parton distributions is discussed in the limit of vanishing skewedness parameter $\zeta$, i.e. when the off-forwardness is purely transverse.…
We discuss the structure functions and the parton distributions in the virtual photon target, both polarized and unpolarized, beyond the leading order in QCD. We study the factorization-scheme dependence of the parton distributions.
COMPASS is a fixed target experiment at the CERN SPS, with a rich physics program focused on nucleon spin structure and on hadron spectroscopy. One of the main goals of the spin program is the measurement of the transverse spin distribution…
A complete, fundamental understanding of the proton must include knowledge of the underlying spin structure. The transversity distribution, $h_1\left(x\right)$, which describes the transverse spin structure of quarks inside of a…
Within the theoretical framework we apply, a suggested origin for single spin asymmetries is the presence of gauge links in transverse momentum dependent distribution functions. Recently we found new gauge link structures in a number of…
A pedagogical presentation of single-spin asymmetries and transversity is offered. Detailed discussion is given of various aspects of single-spin asymmetries in lepton-nucleon and in hadron-hadron scattering and of the role of perturbative…
We study the single spin asymmetry in the lepton angular distribution of Drell-Yan processes in the frame work of collinear factorization. The asymmetry has been studied in the past and different results have been obtained. In our study we…
The most recent data on the weighted transverse single spin asymmetry $A_{UT}^{\sin(\phi_h-\phi_S)}$ from HERMES and COMPASS collaborations are analysed within LO parton model with unintegrated parton distribution and fragmentation…
We develop the theoretical framework for semi-inclusive deep-inelastic scattering on a polarized spin-1 target and apply it to scattering on the polarized deuteron with spectator nucleon tagging. In Part I (this article) we present the…
A brief overview of various problems related to the description of a polarized proton in quark models is presented. Structure functions are discussed both for longitudinal and transverse polarization. A recently introduced quantity,…