Related papers: The QCD Evolution of the Sivers Function
We perform the global analysis of polarized Semi-Inclusive Deep Inelastic Scattering (SIDIS), pion-induced polarized Drell-Yan (DY), and $W^\pm/Z$ boson production data and extract the Sivers function for $u$, $d$, $s$ and for sea-quarks.…
In the TMD approach, the average transverse momentum of the unpolarised TMD PDFs and FFs is crucial not only to reproduce unpolarised cross sections and hadron multiplicities, but also for the understanding of azimuthal and spin…
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…
Single transverse-spin asymmetries have been studied intensively both in experiment and theory. Theoretically, two factorization approaches have been proposed. One is by using transverse-momentum-dependent factorization and the asymmetry…
The properties and behaviour of the solutions of the recently obtained $k_t$-dependent evolution equations are investigated. When used to reproduce transverse momentum spectra of hadrons in Semi-Inclusive DIS, an encouraging agreement with…
We use Lorentz invariance and the QCD equations of motion to study the evolution of functions that appear at leading (zeroth) order in a 1/Q expansion in azimuthal asymmetries. This includes the evolution equation of the Collins…
We present the calculation of the leading contribution to the quark Sivers function at small-Bjorken $x$. This calculation uses the high energy scattering approximation and operator formalism developed by Kovchegov and Sievert to obtain a…
We show that soft-gluon twist-3 contributions to single-spin asymmetries (SSA) in hard processes may be expressed in the form of effective T-odd Sivers distributions, whose signs and scales are modified by process-dependent colour factors.…
A formalism is presented to evaluate the Sivers function in constituent quark models. A non-relativistic reduction of the scheme is performed and applied to the Isgur-Karl model. The sign for the $u$ and $d$ flavor contributions that we…
The large-$x$ behavior of the transverse-momentum dependent quark distributions is analyzed in the factorization-inspired perturbative QCD framework, particularly for the naive time-reversal-odd quark Sivers function which is responsible…
We reconsider the evolution equations for transverse momentum dependent distributions recently proposed by us and recast them in a form which allows the comparison with results recently appeared in the literature. We show under which…
We develop a formalism to evaluate the Sivers function. The approach is well suited for calculations which use constituent quark models to describe the structure of the nucleon. A non-relativistic reduction of the scheme is performed and…
Following the TMD evolution scheme recently proposed for the unpolarized and the Sivers distribution function, we propose a simple strategy to take into account this TMD Q^2 dependence in our phenomenological extraction of the Sivers…
In the preparation period for precision measurements in the newly planned collider experiments, the understanding of the 3D structure of hadron is becoming increasingly urgent. This triggers the activities to include elements of Transverse…
We apply the transverse momentum dependent factorization formalism to investigate the transverse single spin dependent Collins asymmetry with a $\sin(\phi_h+\phi_s)$ modulation in the semi-inclusive production of Kaon meson in deep…
We investigate the single transverse-spin asymmetry with a $\sin (\phi_h-\phi_S)$ modulation in the charged Kaon produced and in $\Lambda$ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent…
We compute the contribution of twist-2 and twist-3 parton distribution functions to the small-$b$ expansion for transverse momentum dependent (TMD) distributions at all powers of $b$. The computation is done by the twist-decomposition…
We estimate Sivers asymmetry in low virtuality photoproduction of $J/\psi$ using color evaporation model and taking into account $Q^2$- evolution of transverse momentum dependent PDF's and Sivers function. There is a substantial reduction…
The semi-inclusive deep-inelastic scattering (SIDIS) is the golden process for investigating the nucleon's transverse momentum-dependent (TMD) structure. We present the complete expression for SIDIS structure functions in the TMD…
The study of the Sivers effect, describing correlations between the transverse polarization of the nucleon and its constituent (unpolarized) parton's transverse momentum, has been the topic of a great deal of experimental, phenomenological…