Related papers: Transversity distributions and spin asymmetries
Using a previous extraction of the quark Boer-Mulders distributions from semiinclusive deep inelastic scattering data, we fit the unpolarized Drell-Yan data on the $\cos 2 \phi$ asymmetry, determining the antiquark Boer-Mulders…
Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when the target and/or quark are transversely polarized. Connections between this…
Polarized flavor asymmetry Delta u-bar/Delta d-bar is investigated in a meson-cloud model. A polarized nucleon splits into a rho meson and a baryon, then the polarized rho meson interacts with the virtual photon. Because of the difference…
We discuss transverse polarization distribution and fragmentation functions, in particular, T-odd functions with transverse momentum dependence, which might be relevant for the description of single transverse spin asymmetries. The role of…
Transverse momentum dependent distribution and fragmentation functions of unpolarized quarks inside unpolarized protons are extracted, for the first time, through a simultaneous analysis of semi-inclusive deep-inelastic scattering,…
We apply the joint threshold and transverse momentum dependent (TMD) factorization theorem to introduce new threshold-TMD distribution functions, including threshold-TMD parton distribution functions (PDFs) and fragmentation functions…
We present a first attempt at a global fit of unpolarized quark transverse momentum dependent distribution and fragmentation functions from available data on semi-inclusive deep-inelastic scattering, Drell-Yan and $Z$ boson production…
Transition generalized parton distributions have emerged as a novel tool for studying the quantum chromodynamics (QCD) structure of resonances. They provide an integrated picture of the transition form factors and the transition parton…
The complete knowledge of the nucleon spin structure at leading twist requires also addressing the transverse spin distribution of quarks, or transversity, which is yet unexplored because of its chiral-odd nature. Elaborating strategies to…
The forward Drell--Yan process in $pp$ scattering at the LHC at $\sqrt{S}=14$ TeV is considered. We analyze the Drell--Yan structure functions assuming the dominance of a Compton-like emission of a virtual photon from a fast quark…
The quark-parton model calculation including the effects of intrinsic transverse momentum and of all six twist-two distribution functions of quarks in polarized nucleons is performed. It is demonstrated that new twist-two quark distribution…
We present QCD corrections to the Drell-Yan process in the transversely polarized, longitudinally polarized and unpolarized cases. The analytical results are presented in a form valid for all $n$-dimensional regularization schemes. A…
There is considerable controversy about the size and importance of nonperturbative contributions to the evolution of transverse-momentum-dependent (TMD) parton distribution functions. Standard fits to relatively high-energy Drell-Yan data…
The $1/N_c$-expansion of QCD suggests large flavor asymmetries of the polarized antiquark distributions in the nucleon. This is confirmed by model calculations in the large-$N_c$ limit (chiral quark-soliton model), which give sizable…
We calculate the $\cos2\phi$ azimuthal asymmetry of the unpolarized $p\bar{p}$ Drell-Yan dilepton production process in the $Z$-resonance region at the Tevatron kinematic domain. Such an azimuthal asymmetry can provide additional…
We present an extraction of the unpolarized transverse-momentum-dependent parton distribution and fragmentation functions that takes into account possible differences between quark flavors and final-state hadrons. The extraction is based on…
First measurements of azimuthal asymmetries in hadron-pair production in deep-inelastic scattering of muons on transversely polarised ^6LiD (deuteron) and NH_3 (proton) targets are presented. The data were taken in the years 2002-2004 and…
We review what is currently known about the transverse spin structure of hadrons, in particular from observables that can be analyzed within a collinear framework. These effects have been around for 40 years and represent a critical test of…
A new method is suggested for the extraction of $u$-quark and $d$-quark transversity distributions, using single spin asymmetry (SSA) data in semi-inclusive deep inelastic scattering (SIDIS) processes, where they couple to the Collins or…
The transverse momentum dependent (TMD) factorization theorem accommodates various types of power corrections. Among them, the least studied are qT/Q corrections, which become significant at large values of transverse momentum. These…