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O. Shevchenko

Publications and source records attributed to O. Shevchenko.

4 recordsLinked to original sources

Polarized parton distributions from NLO QCD analysis of world DIS and SIDIS data

The combined analysis of polarized DIS and SIDIS data is performed in NLO QCD. The new parametrization on polarized PDFs is constructed. The uncertainties on PDFs and their first moments are estimated applying the modified Hessian method. The especial attention is paid to the impact of novel SIDIS data on the polarized distributions of light sea and strange quarks. In particular, the important question of polarized sea symmetry is studied in comparison with the latest results on this subject.

hep-ph

Transversity and T-odd PDFs from Drell-Yan processes with $pp$, $pD$ and $DD$ collisions

We estimate the single-spin asymmetries (SSA) which provide the access to transversity as well as to Boer-Mulders and Sivers PDFs via investigation of the single-polarized Drell-Yan (DY) processes with $ pp$, $pD$ and $DD$ collisions available to RHIC, NICA, COMPASS, and J-PARC. The feasibility of these SSA is studied with the new generator of polarized DY events. The performed estimations demonstrate that there exist the such kinematical regions where SSA are presumably measurable. The most useful for PDFs extraction are the limiting kinematical ranges, where one can neglect the sea PDFs contributions which occur at large values of Bjorken x. It is of interest that on the contrary to the Sivers PDF, the transversity PDF is presumably accessible only in the especial kinematical region. On the contrary to the option with the symmetric collider mode (RHIC, NICA), this is of importance for the COMPASS experiment and the future J-PARC facility where the fixed target mode is available.

hep-ph

On duality of Drell-Yan and J/psi production processes

It is studied the model on J/psi production allowing to extract parton distribution functions (PDFs) from the combined analysis with both data on Drell-Yan and J/psi production processes. It is shown that this, so attractive from theoretical point of view, model, can be safely used in the low energy region E<100 GeV. The significance of gluon contributions to the J/psi cross-sections is investigated. The obtained results in the high energy region occur to be rather surprising.

hep-ph

Transversity and its accompanying T-odd distribution from Drell-Yan processes with pion-proton collisions

It is studied the possibility of direct extraction of the transversity and its accompanying T-odd parton distribution function (PDF) from Drell-Yan (DY) processes with unpolarized pion beam and with both unpolarized and transversely polarized proton targets. At present, such a measurement can be performed on the COMPASS experiment at CERN. The preliminary estimations performed for COMPASS kinematic region demonstrate that it is quite real to extract both transversity and its accompanying T-odd PDF in the COMPASS conditions

hep-ph