6 research outputs found
Recent data analysis to revisit the spin structure function of nucleon in Laplace space
Considering a fixed-flavor number scheme and based on laplace transdormation,
we perform a leading-order and next-to-leading-order QCD analysis which are
including world data on polarized structure functions and . During
our analysis, taking the DGLAP evolution, we employ the Jacobi polynomials
expansion technique. In our recent analysis we utilize the recent available
data and consequently include more data than what we did in our previous
analysis. we obtain good agreements between our results for the polarized
parton densities and nucleon structure functions with all available
experimental data and some common parametrization models.Comment: 16 pages,11 figures, 5 table
Effect of symmetry breaking of polarized light sea quarks on the nucleon and nuclear structure functions, and sum rules
In this study, we performed calculations and analyses of the structure
functions of polarized nucleons and light nuclei, specifically He and
H, using second-order Feynman diagrams. Our investigation focused on two
main aspects: Firstly, we examined the symmetry properties of polarized light
sea quarks. Secondly, we conducted a detailed investigation into the impacts of
symmetry breaking on the structure functions of both nucleons and nuclei. To
achieve this, we utilized the existing polarized Parton Distribution Functions
(polarized PDFs) available in the literature. These PDFs were used to calculate
and compare the polarized structure functions and of the nuclei.
Additionally, we examined and analyzed the Bjorken and Efremov-Leader-Teryaev
sum rules by utilizing the moments of the polarized structure functions. The
Lorentz color force components, namely and , are
determined using the twist-2, twist-3, and twist-4 matrix elements. When
symmetry breaking is applied, it is observed that they have similar magnitudes
but opposite signs. Our theoretical predictions for the polarized structure
functions of nucleons and light nuclei, taking into account the symmetry
breaking of light sea quarks, exhibit better agreement with experimental data.Comment: 13 pages, 12 figures, 3 table
Impacts of EMC effects on the D meson modification factor in equilibrating QGP
In this article we employ the nuclear EMC effect to extract the parton
distribution functions (PDFs) inside the Lead (Pb) and Gold (Au) nuclei.
Extracted PDFs are utilized to obtain the transverse momentum dependent (TMD)
ones, using the computing codes like Pythia 8 or MCFM-10. Through this
procedure TMDPDFs for charm and bottom quarks in Au at
, Pb at and
are calculated. To evaluate the validity of results
and investigate the influence of nuclear EMC effect, the numerated TMDs are
used as input to estimate heavy quark modification factor at
transverse plane . This observable is calculated through numerical
solution of the Fokker-Planck equation. For this purpose we need to extract the
drag and diffusion coefficients, using the hard thermal loop correction. It is
done in the frame work of the relativistic hydrodynamics up to the third order
approximation of gradient expansion. The results are compared with same
solutions when the input PFDs are considered inside the unbounded protons where
the nuclear effect is not included. The comparison indicates a significant
improvement of computed with available experimental data when the EMC
effect is considered.Comment: 16 pages 6 figures 1 table
Nuclear parton distribution functions with uncertainties in a general mass variable flavor number scheme
In this article, we obtain a new set of nuclear Parton distribution functions (nuclear PDFs) at next-to-leading order and next-to-next-to-leading order accuracy in perturbative QCD. The common nuclear deep-inelastic scattering (DIS) data analyzed in our study are complemented by the available charged-current neutrino DIS data with nuclear targets and data from Drell-Yan cross-section measurements for several nuclear targets. In addition, the most recent DIS data from the Jefferson Lab CLAS and Hall C experiments are also added to our data sample. For these specific datasets, we consider the impact of target mass corrections and higher twist effects which are expected to be important in the region of large x and intermediate-to-low Q2. Our analysis is based on a publicly available open-source tool, APFEL, which has been modified to be applicable for our analysis of nuclear PDFs. Heavy-quark contributions to nuclear DIS are considered within the framework of the FONLL general-mass variable-flavor-number scheme. The most recent CT18 PDFs are used as baseline proton PDFs. The uncertainties of nuclear PDFs are determined using the standard Hessian approach. The results of our global QCD analysis are compared with existing nuclear PDF sets and with the fitted cross-sections, for which our set of nuclear PDFs provides a very good description