scholarly journals Global analysis of nuclear parton distribution functions and their uncertainties at next-to-next-to-leading order

2016 ◽  
Vol 93 (1) ◽  
Author(s):  
Hamzeh Khanpour ◽  
S. Atashbar Tehrani
Keyword(s):  
Parton Distribution ◽  
Global Analysis ◽  
Distribution Functions ◽  
Leading Order ◽  
Parton Distribution Functions

scholarly journals CAN POLARIZED DRELL-YAN SHED MORE LIGHT ON THE PROTON SPIN?

1992 ◽  
Vol 07 (29) ◽  
pp. 2695-2702 ◽  
Author(s):  
PRAKASH MATHEWS ◽  
V. RAVINDRAN
Keyword(s):  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Parton Distribution ◽  
Factorization Method ◽  
Distribution Functions ◽  
Proton Spin ◽  
Leading Order ◽  
Parton Distribution Functions ◽  
First Moment ◽  
Polarized Deep Inelastic Scattering

We analyze polarized Drell-Yan process using the factorization method and derive operator definitions for polarized parton distribution functions. We demonstrate that a factorization analogous to that in the unpolarized Drell-Yan case holds in this process. We study the leading order gluonic contribution to the first moment of polarized Drell-Yan function and show that it is consistent with the results obtained from polarized deep inelastic scattering.

Transverse momentum dependent (TMD) parton distribution functions generated in the modified DGLAP formalism based on the valence-like distributions

2017 ◽  
Vol 32 (19n20) ◽  
pp. 1750121 ◽  
Author(s):  
H. Hosseinkhani ◽  
M. Modarres ◽  
N. Olanj
Keyword(s):  
Transverse Momentum ◽  
Parton Distribution ◽  
Dynamical Variable ◽  
Distribution Functions ◽  
Present Calculation ◽  
Leading Order ◽  
Parton Distribution Functions ◽  
Transverse Momentum Dependent ◽  
Longitudinal Structure Function ◽  
Wide Range

Transverse momentum dependent (TMD) parton distributions, also referred to as unintegrated parton distribution functions (UPDFs), are produced via the Kimber–Martin–Ryskin (KMR) prescription. The GJR08 set of parton distribution functions (PDFs) which are based on the valence-like distributions is used, at the leading order (LO) and the next-to-leading order (NLO) approximations, as inputs of the KMR formalism. The general and the relative behaviors of the generated TMD PDFs at LO and NLO and their ratios in a wide range of the transverse momentum values, i.e. [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] are investigated. It is shown that the properties of the parent valence-like PDFs are imprinted on the daughter TMD PDFs. Imposing the angular ordering constraint (AOC) leads to the dynamical variable limits on the integrals which in turn increase the contributions from the lower scales at lower [Formula: see text]. The results are compared with our previous studies based on the MSTW2008 input PDFs and it is shown that the present calculation gives flatter TMD PDFs. Finally, a comparison of longitudinal structure function [Formula: see text] is made by using the produced TMD PDFs and those that were generated through the MSTW2008-LO PDF from our previous work and the corresponding data from H1 and ZEUS collaborations and a reasonable agreement is found.

scholarly journals Polarized parton distribution functions: parametrization and transverse momentum dependence

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
H. Nematollahi ◽  
P. Abolhadi ◽  
S. Atashbar ◽  
A. Mirjalili ◽  
M. M. Yazdanpanah
Keyword(s):  
Data Analysis ◽  
Transverse Momentum ◽  
Parton Distribution ◽  
Jacobi Polynomials ◽  
Global Analysis ◽  
Distribution Functions ◽  
Momentum Dependence ◽  
Parton Distribution Functions ◽  
Transverse Momentum Dependent ◽  
Transverse Momentum Dependence

AbstractWe extract the polarized parton distribution functions (PPDFs) of proton. To this end we do a global analysis on recent and up-to-dated experimental data of polarized nucleon and deuteron structure functions at the NLO accuracy of perturbative QCD. We use the Jacobi polynomials expansion technique to do the required analyses. To achieve a more realistic estimation of the PPDFs and observable uncertainties we employ the Hessian error propagation. Following that we apply a theoretical approach which is based on imposing Lorentz structure in the parton model to investigate the transverse momentum dependence of these PPDFs. In this approach, the transverse momentum dependent (TMD) polarized parton distributions, which are also called the helicity distributions, are related to the integrated ones. This relation is indicating the priority and importance of data analysis for PPDFs. The results show a convenient general treatment expected for TMD densities which are in fact resulted from data analysis and fitting processes of integrated PPDFs in an adequate and a proper way.

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