Related papers: Interference Fragmentation Functions and the Nucle…
The thesis is devoted to the study of the fragmentation process of polarized quarks, and in particular of the Collins effect used for the extraction of the quark transversity distribution. The aim is to include the spin degree of freedom in…
We discuss the production of hadrons in polarized lepton nucleon interactions and in the current jet fragmentation region; using the QCD hard scattering formalism we compute the helicity density matrix of the hadron and show how its…
The transverse structure of the nucleon as probed in hard exclusive processes plays critical role in the understanding of the structure of the underlying event in hard collisions at the LHC, and multiparton interactions. We summarize…
A better understanding of transverse momentum (k_T-) dependent quark distributions in a hadron is needed to interpret several experimentally observed large angular asymmetries and to clarify the fundamental role of gauge links in…
We present a new analysis of the helicity parton distributions of the nucleon. The analysis takes into account the available data from inclusive and semi-inclusive polarized deep inelastic scattering, as well as from polarized pp scattering…
I review what is known about the quark and gluon spin distributions in the nucleon. I discuss in some detail (a) the existence of sum rules for angular momentum; (b) the interpretation and possible measurement of the nucleon's transversity…
We show how the transverse polarization of a quark initiating a jet can be probed by the azimuthal distribution of two hadrons (of large $z$) in the jet. This permits a twist 2 asymmetry in hard processes when only one of the initial…
We present the systematic results for three dimensional fragmentation functions of spin one hadrons defined via quark-quark correlator. There are totally 72 such fragmentation functions, among them 18 are twist-2, 36 are twist-3 and 18 are…
We analyze polarization phenomena for pseudoscalar and vector mesons production in nucleon-nucleon collisions. We identify three energy regions corresponding to different physics and different approaches in the analysis of polarization…
The Sivers Function is briefly reviewed and the Collins Fragmentation Function to produce a hadron from a polarized quark is defined. We estimate $\pi^{+},\pi^{-}$ +X production, where X represents particles which are not detected, via…
We apply the $k_T$-factorization approach to the production of $\phi$ meson in deep-inelastic scattering. The helicity-conserving $\gamma^*(T,L) \to \phi$ impact factor is calculated for longitudinal and transverse photon polarization using…
Quarks and gluon, as quantum particles, are subjects to various effects that go beyond the naive parton picture and are not captured by ordinary parton densities. In this work, we investigate the twist-three parton distribution functions,…
This talk presents results from the QCDSF-UKQCD collaboration for moments of leading twist generalized parton distributions in two-flavor lattice QCD based on O(a) improved Wilson Fermions. We study helicity independent and helicity flip…
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…
A summary is given of the experimental and theoretical results presented in the working group on spin physics. New data on inclusive and semi-inclusive deep-inelastic scattering, combined with theoretical studies of the polarized…
We summarize the latest achievements about the extraction of the transversity parton distribution and proton tensor charge based on an analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets.…
Nucleon spin structure functions have been investigated mainly by longitudinally-polarized ones for finding the origin of the nucleon spin. Other types of spin structure functions are transversely-polarized ones. In particular, quark…
Quark-quark double scattering in eA DIS and its contribution to quark and anti-quark fragmentation functions are investigated with the generalized factorization of the relevant twist-four processes in pQCD. It is shown that the resulting…
We review applicability of QCD factorization theorem to multiple scattering in deeply inelastic lepton-nucleus scattering. We show why A^{1/3}-type nuclear enhancement can be calculated consistently in perturbative QCD. We derive the…
We considered the electro- and photoproduction of \rho and other vector mesons with moderately large transverse momentum in the scattering of unpolarized electrons on unpolarized nucleons and nuclei. For these processes we have analyzed how…