Related papers: GPD's and Ssa's
We investigate the emergence of single spin asymmetries (SSA) in hard processes using transverse momentum dependent (TMD) distribution and fragmentation functions. Specifically, the description of SSA involves time reversal-odd functions.…
We investigate the helicity dependent generalized parton distributions (GPDs) in momentum as well as transverse position (impact) spaces for up and down quarks in a proton when the momentum transfer in both the transverse and longitudinal…
We summarize recent developments in understanding the concept of generalized parton distributions (GPDs), its relation to nucleon structure, and its application to high-Q2 electroproduction processes. Following a brief review of QCD…
We study parity-even and parity-odd polarization observables for the process $p \, p \to l^{\pm} \, X$, where the lepton comes from the decay of a $W$-boson. By using the collinear twist-3 factorization approach, we consider the case when…
I review progress on selected issues connected with generalized parton distributions. Topics range from the description of hard exclusive reactions to the spatial distribution of quarks in the nucleon and the contribution of their orbital…
Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, are exhibit a significant deviation from axial symmetry when the target and/or quark is transversely polarized. From this deformation, we…
The proton spin puzzle issue focused the attention on the parton spin and orbital angular momentum contributions to the proton spin. However, a complete characterization of the proton spin structure requires also the knowledge of the parton…
I shall present a rather pedagogical discussion of the transversity distributions in the quark-parton model and, in particular, the role of perturbative QCD corrections. Among the topics I shall discuss are: LO and NLO evolution, the Soffer…
Using the linear sigma model to describe quark--pion interactions, we compute polarization asymmetries in quark fragmentation. We show that the effects of transverse quark polarizations appear in the correlation between the two leading…
Information on the Sivers distribution and the Collins fragmentation functions and their transverse momentum dependence is mainly based on fitting single spin asymmetry data from semi-inclusive deep inelastic scattering (SIDIS). Independent…
We study the small-$x$ asymptotics of unpolarized generalized parton distributions (GPDs) and generalized transverse momentum distributions (GTMDs). Unlike the previous works in the literature, we consider the case of non-zero (but small)…
The transversity distribution was recently extracted from deep-inelastic scattering processes producing hadron pairs in the final state. Together with a specific chiral-odd di-hadron fragmentation function, it is involved in the elementary…
The combination of transverse momentum and polarization effects in hard scattering processes, e.g polarized deep-inelastic leptoproduction, results in a rich variety of information on the hadronic structure. This information is encoded in a…
We study the chiral-even generalized parton distributions (GPDs) of $\bar{u}$ and $\bar{d}$ quarks at zero skewness using the overlap representation within the light cone formalism. The GPDs of $\bar{u}$ and $\bar{d}$ quarks can be…
We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space and combine in a single picture all the information contained in the generalized parton distributions (GPDs) and…
Recent work suggests non-trivial relations between generalized parton distributions on the one hand and (naive time-reversal odd) transverse momentum dependent distributions on the other. Here we review the present knowledge on such type of…
Transversity generalized parton distributions (GPDs) can be probed in diffractive electro- and photoproduction of two vector mesons on a hadron in kinematics where the two vector mesons are separated by a large rapidity gap. We report on…
The $\rho$ meson polarized generalized parton distribution functions, its structure functions $g_1$ and $g_2$ and its axial form factors ${\tilde G}_{1,2}$ are studied based on a light-front quark model for the first time. Comparing our…
A short review of single spin asymmetries in deep inelastic semi-inclusive processes, connected with prediction of chiral quark-soliton model for the nucleon transversity distributions, its possible theoretical understanding in the…
Transverse-momentum dependent parton distributions (TMDs) are studied in the framework of quark models. In particular, quark model relations among TMDs are reviewed and their physical origin is discussed in terms of rotational-symmetry…