scholarly journals Decoupling the NLO-coupled QED⊗QCD, DGLAP evolution equations, using Laplace transform method

2017 ◽  
Vol 32 (14) ◽  
pp. 1750065 ◽  
Author(s):  
Marzieh Mottaghizadeh ◽  
Parvin Eslami ◽  
Fatemeh Taghavi-Shahri
Keyword(s):  
Laplace Transform ◽  
Structure Function ◽  
Evolution Equations ◽  
Distribution Functions ◽  
Proton Structure Function ◽  
Dglap Evolution ◽  
Leading Order ◽  
Laplace Transform Method ◽  
Transform Method ◽  
Proton Structure

We analytically solved the QED[Formula: see text]QCD-coupled DGLAP evolution equations at leading order (LO) quantum electrodynamics (QED) and next-to-leading order (NLO) quantum chromodynamics (QCD) approximations, using the Laplace transform method and then computed the proton structure function in terms of the unpolarized parton distribution functions. Our analytical solutions for parton densities are in good agreement with those from CT14QED [Formula: see text] (Ref. 6) global parametrizations and APFEL (A PDF Evolution Library) [Formula: see text] (Ref. 4). We also compared the proton structure function, [Formula: see text], with the experimental data released by the ZEUS and H1 collaborations at HERA. There is a nice agreement between them in the range of low and high [Formula: see text] and [Formula: see text].

NNLO LONGITUDINAL PROTON STRUCTURE FUNCTION, BASED ON THE MODIFIED χQM

2012 ◽  
Vol 27 (31) ◽  
pp. 1250179 ◽  
Author(s):  
H. NEMATOLLAHI ◽  
M. M. YAZDANPANAH ◽  
A. MIRJALILI
Keyword(s):  
Structure Function ◽  
Gluon Distribution ◽  
Distribution Functions ◽  
Proton Structure Function ◽  
Chiral Quark Model ◽  
Leading Order ◽  
Longitudinal Structure ◽  
Proton Structure ◽  
Longitudinal Structure Function ◽  
Good Agreement

We compute the longitudinal structure function of the proton (FL) at the next-to-next-to-leading order (NNLO) approximation. For this purpose, we should know the flavor-singlet, non-singlet and gluon distribution functions of the proton. We use the chiral quark model (χQM) to determine these distributions. Finally, we compare the results of FL with the recent ZEUZ and H1 experimental data and some fitting parametrizations. Our results are in good agreement with the data and the related fittings.

scholarly journals Fragmentation functions of neutral mesons π0 and k0 with Laplace transform approach

2016 ◽  
Vol 31 (17) ◽  
pp. 1650100 ◽  
Author(s):  
F. Taghavi-Shahri ◽  
S. Atashbar Tehrani ◽  
M. Zarei
Keyword(s):  
Experimental Data ◽  
Laplace Transform ◽  
Evolution Equations ◽  
Dglap Evolution ◽  
Laplace Transform Method ◽  
Transform Method ◽  
Neutral Mesons ◽  
The Laplace Transform ◽  
Fragmentation Functions ◽  
Good Agreement

With an analytical solutions of DGLAP evolution equations based on the Laplace transform method, we find the fragmentation functions (FFs) of neutral mesons, [Formula: see text] and [Formula: see text] at NLO approximation. We also calculated the total fragmentation functions of these mesons and compared them with experimental data and those from global fits. The results show a good agreement between our solutions and other models and they are compatible with experimental data.

DETERMINATION OF THE STRONG COUPLING CONSTANT FROM NLO QCD ANALYSIS OF PROTON STRUCTURE FUNCTION

2011 ◽  
Vol 26 (03n04) ◽  
pp. 658-659 ◽  
Author(s):  
H. KHANPOUR ◽  
ALI N. KHORRAMIAN ◽  
S. ATASHBAR TEHRANI
Keyword(s):  
Structure Function ◽  
Perturbative Qcd ◽  
Strong Coupling ◽  
Distribution Functions ◽  
Strong Coupling Constant ◽  
Proton Structure Function ◽  
Coupling Constant ◽  
Proton Structure ◽  
Qcd Analysis

In this article we present a determination of the strong coupling constant and parton distribution functions (PDFs) based on a next-to-leading order (NLO) perturbative QCD analysis of proton structure function. More precisely, we extract [Formula: see text] and PDFs by fitting perturbative QCD predictions to the data from the measurements of the proton structure function [Formula: see text] in deep inelastic scattering, which are based on perturbative QCD calculations up to NLO. We obtain at NLO [Formula: see text] in the variable-flavor number scheme.

scholarly journals A phenomenological solution small x to the longitudinal structure function dynamical behavior

2014 ◽  
Vol 29 (32) ◽  
pp. 1450189 ◽  
Author(s):  
G. R. Boroun ◽  
B. Rezaei ◽  
J. K. Sarma
Keyword(s):  
Structure Function ◽  
Dynamical Behavior ◽  
Structure Functions ◽  
Proton Structure Function ◽  
Leading Order ◽  
Longitudinal Structure ◽  
Proton Structure ◽  
Longitudinal Structure Function ◽  
Color Dipole ◽  
Small X

In this paper, the evolutions of longitudinal proton structure function have been obtained at small x up to next-to-next-to-leading order using a hard Pomeron behavior. In our paper, evolutions of gluonic as well as heavy longitudinal structure functions have been obtained separately and the total contributions have been calculated. The total longitudinal structure functions have been compared with results of Donnachie–Landshoff (DL) model, Color Dipole (CD) model, kT factorization and H1 data.

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