scholarly journals Addendum to: A new numerical method for obtaining gluon distribution functions G(x,Q 2)=xg(x,Q 2), from the proton structure function $F_{2}^{\gamma p}(x,Q^{2})$

2010 ◽  
Vol 68 (3-4) ◽  
pp. 683-685 ◽  
Author(s):  
Martin M. Block
Keyword(s):  
Structure Function ◽  
Numerical Method ◽  
Gluon Distribution ◽  
Distribution Functions ◽  
Proton Structure Function ◽  
Proton Structure

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.

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.

Q2 dependence of the fractional momenta carried by small x quarks and gluons in models of proton structure function

2019 ◽  
Vol 34 (33) ◽  
pp. 1950273
Author(s):  
Luxmi Machahari ◽  
D. K. Choudhury
Keyword(s):  
Structure Function ◽  
Gluon Distribution ◽  
Taylor Expansion ◽  
Total Momentum ◽  
Analytical Models ◽  
Proton Structure Function ◽  
Self Similarity ◽  
Theor Phys ◽  
Proton Structure ◽  
Small X

Recently, we suggested two alternative analytical models of proton structure function [Formula: see text] and gluon distribution [Formula: see text] at small [Formula: see text] [L. Machahari and D. K. Choudhury, Eur. Phys. J. A 54, 69 (2018); Commun. Theor. Phys. 71, 56 (2019)] derived from the coupled DGLAP equations for quarks and gluons approximated by Taylor expansion. In this work, we compute the partial momentum fractions carried by quarks and gluons in limited small [Formula: see text] range: [Formula: see text] and compare them with few other models available in the current literature. The analysis leads to understand qualitatively the effects of notions like Froissart saturation and self-similarity in the proton at small [Formula: see text]. We also study if our results conform to the total momentum fractions as predicted in perturbative and lattice QCD.

Parton Distribution Functions and models of proton structure functions with self-similarity

2016 ◽  
Vol 31 (34) ◽  
pp. 1650176 ◽  
Author(s):  
D. K. Choudhury ◽  
Baishali Saikia
Keyword(s):  
Structure Function ◽  
Initial Conditions ◽  
Parton Density ◽  
Distribution Functions ◽  
Proton Structure Function ◽  
Model Parameters ◽  
Self Similarity ◽  
Parton Density Function ◽  
Transverse Momentum Dependent ◽  
Proton Structure

Sometime back, a self-similarity based model of the proton structure function at small [Formula: see text] was proposed by Lastovicka. We make reanalysis of this model with most recent HERA data. No significance difference with the earlier analysis is found. Both the analyses have singularity within the kinematical range of [Formula: see text]: [Formula: see text]. We therefore study the model with the additional assumption that it should be singularity free, imposing positivity conditions on the model parameters. This results in a new model which is, however, phenomenologically valid only in a limited low [Formula: see text] range. We therefore make further generalization of the defining self-similar unintegrated Parton Density Function (uPDF) and show that the with proper generalizations and initial conditions on them not only remove the undesired singularity but also results in a structure function with logarithmic growth in [Formula: see text] closer to QCD. The phenomenological range of validity is then found to be much larger than the earlier versions. We also extrapolate the models to large [Formula: see text] in a parameter-free way. The possibility of incorporation of Transverse Momentum Dependent (TMD) PDF in this approach is explored as well.

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