arXiv subjects

G. R. Boroun

Publications and source records attributed to G. R. Boroun.

At least 73 records · Page 4Linked to original sources

arXiv2020

The study of the gluon distribution function and reduced cross section behavior using the proton structure function

The behavior of the gluon distribution function and the reduced cross section considered from the proton structure function and its derivatives at low values of $x$. These behaviors studied and compared with the experimental data. These results are augmented by including an additional higher-twist term in the description of the nonlinear correction. This additional term, modified nonlinear correction, improves the description of the reduced cross sections significantly at low values of $Q^{2}$. We discuss, furthermore, how this behavior can be determine the reduced cross section with respect to the proton parameterization at high-y values. The resulting predictions for $σ_{r}$ suggest that further corrections are required for $Q^{2}$ less than about $3~\mathrm{GeV}^{2}$.

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arXiv2020

Longitudinal structure function from the parton parameterization

We present a set of formulas to extract the longitudinal structure function from the proton structure function and its derivatives with respect to lnQ2 in the next-to-next-to-leading order of the perturbative theory at low x based on a hard poemron exchange. The behavior of the DIS cross section ratio R(x;Q2) and the ratio FL(x;Q2)=F2(x;Q2) studied and compared with the experimental data, also these behaviors controlled by the color dipole model bound. These results show a good agreement with the DIS experimental data throughout the low values of x. These results within the next-to-next-to-leading order approximation at very low x can be applied in the LHeC region for analyses of ultra-high energy processes.

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arXiv2020

Searching for top quark pair production cross section at LHeC and FCC-eh

The deep inelastic scattering mode of $t\overline{t}$ pair production at the proposed LHeC and FCC-eh is considered. We present a method to extract the top reduced cross section related to the transversal structure function $F_{2}(x,Q^{2})$ parameterization. Numerical calculations with known kinematics of the LHeC and FCC-eh colliders are demonstrated. The results obtained for charm and beauty pair production are comparable with the experimental data. We show that for a wide range of the momentum transfer into the top quark pair, the reduced cross section is well described by center-of-mass energies.

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arXiv2020

The Color Dipole Picture and extracting the ratio of structure functions at small $x$

We present a set of formulas to extract the ratio $F_{L}(x,Q^{2})/F_{2}(x,Q^{2})$ and $R(x,Q^{2})$ from the proton structure function parameterized in the next-to-next-to-leading order of the perturbative theory at low $x$ values. The behavior of these ratios are considered with respect to the power-law behavior of the proton structure function. The results are compared with experimental data and the color dipole model bounds. These ratios are in good agreement with the HERA data throughout the fixed value of the invariant mass. The behavior of these ratios controlled by the nonlinear corrections at low values of $Q^{2}$. These results and comparison with HERA data demonstrate that the suggested method for the ratio of structure functions can be applied in analyses of the LHeC and FCC-eh projects.

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arXiv2019

The exponent of the longitudinal structure function $F_{L}$ at low $x$

We present a set of formula to extract exponents of the longitudinal structure function and reduced cross section from the Regge-like behavior at small $x$. The exponents are found to be independent of $Q^{2}$ at NNLO analysis. As a result, we show that the reduced cross section exponents do not have the same behavior at some values of $x$. This difference predicts the non-linear effects and some evidence for shadowing and antishadowing at LHeC. Also the ratio $\frac{F_{2}}σ$ is calculated and compared with the corresponding HERA data. Our calculations show a very good agreement with the DIS experimental data throughout the small values of $x$.

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arXiv2019

Ratio of the structure functions and the color dipole model bound

We observe that the DGLAP evolution equations at NNLO analysis predicts a ratio of the structure functions in region of small Bjorken variable $x$. The ratio $F_{L}(x,Q^{2})/F_{2}(x,Q^{2})$ is obtained and compared with the prediction of the dipole model and HERA data. In particular we show that this ratio is lower than dipole model bound at high-$Q^{2}$ values and it is higher at low-$Q^{2}$ values . Then the effect of adding a higher twist term to the description of the ratio $F_{L}(x,Q^{2})/F_{2}(x,Q^{2})$ for $Q^{2}< 20~GeV^{2}$ is investigated. Also the bounds are discussed by including charm distribution on $F_{L}/F_{2}$. We discuss, furthermore, how this ratio can be determine the proton structure function with respect to the reduced cross section at high-$y$ values.

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arXiv2019

The behavior of the structure function by using the effective exponent at low-x

An analytical solution of the QCD evolution equations for the singlet and gluon distribution is presented. We decouple DGLAP evolution equations into the initial conditions by using a Laplace transform method at $N^{n}LO$ analysis. The relationship between the nonlinear behavior and color dipole model is considered based on an effective exponent behavior at low-$x$ values. We obtain the effective exponent at NLO analysis from the decoupled behavior of the distribution functions. The proton structure function compared with H1 data from the inclusive structure function $F_{2}(x,Q^{2})$ for $x {\leq}~ 10^{-2}$ and $5 {\leq} Q^{2} {\leq} 250~GeV^{2}$.

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arXiv2018

$\mathcal{O} \,(θ)$ Feynman rules for quadrilinear gauge boson couplings in noncommutative standard model

We examine the electroweak gauge sector of noncommutative standard model and in particular, obtain the $\mathcal{O} \,(θ)$ Feynman rules for all quadrilinear gauge boson couplings. Surprisingly, an electroweak-chromodynamics mixing appears in the gauge sector of noncommutative standard model, where photon as well as the neutral weak boson are coupled directly to three gluons. The phenomenological perspectives of the model in $W^-W^+ \rightarrow Z Z$ scattering are studied and it is shown that there is a characteristic oscillatory behaviour in azimuthal distribution of scattering cross sections which can be interpreted as a direct signal of noncommutative standard model. Assuming the integrated luminosity 100 $\mathrm{fb}^{-1}$, the number of $W^-W^+ \rightarrow Z Z$ subprocesses are estimated for some values of noncommutative scale $Λ_{\mathrm{NC}}$ at different center of mass energies and the results are compared with predictions of the standard model.

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arXiv2018

Longitudinal structure function from logarithmic slopes of $F_{2}$ at low $x$

Using Laplace transform techniques, I calculate the longitudinal structure function $F_{L}(x,Q^{2})$ from the scaling violations of the proton structure function $F_{2}(x,Q^{2})$, and make a critical study of this relationship between the structure functions at leading order (LO) up to next-to-next-to leading order (NNLO) analysis at small $x$. Furthermore, I consider heavy quark contributions to the relation between the structure functions, which leads to compact formula for $N_{f}=3+\mathrm{Heavy}$. The nonlinear corrections to the longitudinal structure function at LO up to NNLO analysis are shown in the $N_{f}=4$ (light quark flavor) based on the nonlinear corrections at $R=2$ and $R=4 GeV^{-1}$. The results are compared to experimental data of the longitudinal proton structure function $F_{L}$ in the range of $6.5 \leq Q^{2} \leq 800 GeV^{2}$.

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arXiv2017

Solution of QCD$\otimes$QED coupled DGLAP equations at NLO

In this work, we present an analytical solution for QCD$\otimes$QED coupled Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations at the leading order (LO) accuracy in QED and next-to-leading order (NLO) accuracy in perturbative QCD using double Laplace transform. This technique is applied to obtain the singlet, gluon and photon distribution functions and also the proton structure function. We also obtain contribution of photon in proton at LO and NLO at high energy and successfully compare the proton structure function with HERA data \cite{12} and APFEL results \cite{7}. Some comparisons also have been done for the singlet and gluon distribution functions with the MSTW results\cite{9}. In addition, the contribution of photon distribution function inside the proton has been compared with results of MRST \cite{11} and with the contribution of sea quark distribution functions which obtained by MSTW \cite{9} and CTEQ6M \cite{14}.

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arXiv2017

Nuclear longitudinal structure function in eA processes at the LHeC

The nucleon and nuclear longitudinal structure functions are determined by the Kharzeev-Levin-Nardin (KLN) model of the low $x$ gluon distribution. The behavior of the gluon distribution ratio $R_{g}={G^{A}}/{AG^{p}}$ and the ratio $R_{L}^{total}={F_{L}^{A-total}}/{AF_{L}^{p-total}}$ in this processes are found. The heavy longitudinal structure function ratios in eA processes at the LHeC region are discussed. Heavy contributions to the ratio of the total longitudinal structure function are considerable and should not be neglected especially at smaller $x$ of the LHeC project. In the KLN model the new geometrical scaling for transition from the linear to nonlinear regions in accordance with the LHeC processes is used, whose results intensively depended on the heavy quarks mass effect.

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arXiv2016

Laguerre polynomials method in the valon model

We used the Laguerre polynomials method for determination of the proton structure function in the valon model. We have examined the applicability of the valon model with respect to a very elegant method, where the structure of the proton is determined by expanding valon distributions and valon structure functions on Laguerre polynomials. We compared our results with the experimental data, GJR parameterization and DL model. Having checked, this method gives a good description for the proton structure function in valon model.

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arXiv2016

The approximation method for calculation of the exponent of the gluon distribution-$λ_{g}$ and the structure function-$λ_{S}$ at low $x$

We present a set of formulae using the solution of the QCD Dokshitzer-Gribov-Lipatov-Altarelli-parisi (DGLAP) evolution equation to the extract of the exponent $λ_g$ gluon distribution and $λ_S$ structure function from the Regge- like behavior at low $x$. The exponents are found to be independent of $x$ and to increase linearly with ln$Q^{2}$ and compared with the most data from H1 Collaboration. We also calculated the structure function $F_{2}(x,Q^{2})$ and the gluon distribution $G(x,Q^{2})$ at low $x$ assuming the Regge- like behavior of the gluon distribution function at this limit and compared with NLO QCD fit to the H$1$ data, two Pomeron fit, multipole Pomeron exchange fit and MRST (A.D.Martin, R.G.Roberts, W.J.Stirling and R.S.Thorne), DL(A.Donnachie and P.V.Landshoff), NLO-GRV(M.Gluk, E.Reya and A.Vogt) fit results, respectively.

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arXiv2016

Analytical approach for the approximate solution of the longitudinal structure function with respect to the GLR-MQ equation at small x

We show that the nonlinear corrections to the longitudinal structure function can be tamed the singularity behavior at low x values, with respect to GLR-MQ equations. This approach can determined the shadowing longitudinal structure function based on the shadowing corrections to the gluon and singlet quark structure functions. Comparing our results with HERA data show that at very low x this behavior completely tamed by these corrections.

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arXiv2016

Solutions of Independent DGLAP Evolution Equations for the Gluon Distribution and Singlet Structure Functions in the Next-to-Leading Order at Low x

We present a set of independent formulae to extract the gluon distribution and singlet structure function from its derivatives with respect to $lnQ^{2}$ in the next- to- leading order of perturbation theory at low-$x$ based on a hard pomeron exchange. In this approach, both singlet quarks and gluons have the same high-energy behavior at small $x$. This approach needs the QCD input parameterizations for a independent DGLAP evolutions that we calculated numerically and compared with MRST, GRV and DL model- the Pomeron has a hard nature. Its evolution gives a good fit to the experimental data. The obtained values are in the range $10^{-4}\hspace{0.1cm}{\leq}\hspace{0.1cm}x\hspace{0.1cm}{\leq}10^{-2}$ at $Q^{2}=20 \hspace{0.1cm}GeV^{2}$.

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arXiv2016

Top reduced cross section behavior at the LHeC kinematic range

The linear and non-linear behavior of the top reduced cross section in the LHeC region is considered concerning the boson-gluon fusion (BGF) model at the deep inelastic scattering leptoproduction. We will show that the nonlinear behavior, at this region, for the $t\overline{t}$ production is very small. Also the behavior of the top reduced cross section and the ratio $R^{t}$ in this processes is considered.

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arXiv2015

Decoupling of the DGLAP evolution equations by Laplace method

In this paper, we derive two second- order of differential equation for the gluon and singlet distribution functions by using the Laplace transform method. We decoupled the solutions of the singlet and gluon distributions into the initial conditions (function and derivative of the function) at the virtuality $Q_{0}^{2}$ separately as these solutions are defined by: \begin{eqnarray} F_{2}^{s}(x,Q^{2}) &=& \mathcal{F}(F_{s0}, \partial F_{s0})\nonumber &&\mathrm{and} \nonumber G(x,Q^{2}) &=& \mathcal{G}(G_{0}, \partial G_{0}).\nonumber \end{eqnarray} We compared our results with the MSTW parameterization and the experimental measurements of $F_{2}^{p}(x,Q^{2})$.

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arXiv2015

The behavior of the heavy-quarks structure functions at small-$x$

The behavior of the charm and bottom structure functions ($F_{k}^{i}(x,Q^{2})$, i=c,b; k=2,L) at small-$x$ is considered with respect to the hard-Pomeron and saturation models. Having checked that this behavior predicate the heavy flavor reduced cross sections concerning the unshadowed and shadowed corrections. We will show that the effective exponents for the unshadowed and saturation corrections are independent of $x$ and $Q^{2}$, and also the effective coefficients are dependent to $\ln{Q^{2}}$ compared to Donnachie-Landshoff (DL) and color dipole (CD) models.

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