相关论文: $\sin (\phi_\Lambda-\phi_S)$ azimuthal asymmetry i…
We examine in detail the diagrammatic mechanisms which provide the change of sign between the single transverse spin asymmetries measured in semi-inclusive deep inelastic scattering (SIDIS) and in the Drell-Yan process (DY). This asymmetry…
We illustrate how an axial asymmetry in impact parameter dependent parton distributions can give rise to an axial asymmetry for the transverse momentum of the leading quark in the photo-production of hadrons. The effect is related to the…
The chiral quark model combined with unitarity and impact parameter picture provides simple semiclassical mechanism for generation of the single-spin asymmetry $A_N$ in the $\pi^0$-production in the polarized proton collisions at RHIC. We…
In semi-inclusive deep inelastic scattering (SIDIS) the non-zero transverse momentum of partons induces azimuthal dependence of the cross-section. For unpolarised nucleon, three azimuthal modulations that can be related to different…
We study the time-reversal odd quark fragmentation function and its consequences on the hard processes. T-odd quark fragmentation function may arise, although QCD is T-invariant, from the non-perturbative dynamics in the fragmentation…
The single-spin asymmetry of unpolarized leptons scattering deep-inelastically off transversely polarized nucleons is discussed. This observable is generated by a two-photon exchange between lepton and nucleon. In a partonic description of…
Preliminary results obtained by the COMPASS experiment for longitudinal-spin-dependent azimuthal asymmetries in single-hadron muoproduction off protons are presented for the first time. The analysis was carried out on the full data sample…
We present calculation on the azimuthal spin asymmetries for pion pair production in semi-inclusive deep inelastic scattering (SIDIS) process at both HERMES and COMPASS kinematics, with transversely polarized proton, deuteron and neutron…
The transverse-momentum-dependent (TMD) factorization theorem for dijet production in deep-inelastic scattering is used here to make predictions of the gluon Sivers function. We revise the previously studied unpolarized case and develop the…
The impact of the inclusion of TMD shape functions on the transverse momentum spectrum in $J/\psi$ production at the EIC is investigated by considering the matching of the TMD factorization description at low transverse momentum with the…
Recently, it has been shown, contrary to previous beliefs, that the k_T distribution of quarks in a transversely polarized proton can be asymmetric. This ``Sivers effect'' had already been used to explain transverse single spin asymmetries…
We study the Sivers effect in transverse single spin asymmetries (SSA) for pion and kaon production in Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes. We perform a fit of A^{sin(phi_h-phi_S)}_UT taking into account the recent…
Using a generalized parton model approach including spin and intrinsic parton motion effects, and assuming the validity of factorization for large-pT jet production in hadronic collisions, we study the azimuthal distribution around the jet…
After reviewing the most important COMPASS results on transverse spin effects in SIDIS, I will present the recent work we have done on weighted Sivers asymmetries and "transversity induced" $\Lambda$ polarisation. Using the high statistics…
We report the first measurement of transverse single-spin asymmetries in $J/\psi$ production from transversely polarized $p+p$ collisions at $\sqrt{s} = 200$ GeV with data taken by the PHENIX experiment in 2006 and 2008. The measurement was…
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; all transverse motions are taken into account. Extraction of the…
We discuss the quark transversity distribution function and a possible way to access it through the measurement of single spin azimuthal asymmetry in semi-inclusive single pion electroproduction on a transversely polarized target.
We compare the relative importance of different mechanisms for polarized $J/\psi$ production in semi-inclusive deep inelastic scattering processes at large $Q^2$. The transverse momentum dependent (TMD) factorization framework and…
Considering the possible interpretation of the Ellis-Jaffe sum rule violation that the strange quark in the polarized proton is remarkably polarized in the opposite direction of the proton spin, we investigate its implication in the…
We present estimates of Single Spin Asymmetry (SSA) in the electroproduction of $J/\psi$ taking into account the transverse momentum dependent (TMD) evolution of the gluon Sivers function and using Color Evaporation Model of charmonium…