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In this paper we re-analyse the situation with the shadowing corrections (SC) in QCD for the proton deep inelastic structure functions. We reconsider the Glauber - Mueller approach for the SC in deep inelastic scattering (DIS) and suggest a…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. L. Ayala Filho , M. B. Gay Ducati , E. M. Levin

Nuclear deep inelastic structure functions F_2^A(x,Q^2) as well as parton distribution functions in a nuclei are investigated in the framework of rescaling model. Our analysis is based on analytical expressions for quark and gluon densities…

High Energy Physics - Phenomenology · Physics 2024-04-11 A. V. Kotikov , A. V. Lipatov , P. M. Zhang

Considering the BFKL and DGLAP QCD evolution equations for structure functions, we discuss the possibility of unifying them in the whole $x$ and $Q^2$ range. We emphasize that the main problem is related to the constraint of angular…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Wallon

The gluon recombination functions in the twist-4 QCD evolution equations are studied at the leading logarithmic approximation using both the covariant and non-covariant methods. We justify that the infrared singularities in the twist-4…

High Energy Physics - Phenomenology · Physics 2013-10-01 Wei Zhu , Zhenqi Shen

We calculate the shadowing of sea quarks and gluons and show that the shadowing of gluons is {\it not} simply given by the sea quark shadowing, especially at small $x$. The calculations are done in the lab frame approach by using the…

High Energy Physics - Phenomenology · Physics 2009-10-31 N. Hammon , H. Stöcker , W. Greiner

An analytical study with respect to the nonlinear corrections for the nuclear gluon distribution function in the next-to-leading order approximation at small $x$ is presented. We consider the nonlinear corrections to the nuclear gluon…

High Energy Physics - Phenomenology · Physics 2024-02-08 G. R. Boroun , B. Rezaei , F. Abdi

We show that the evolution equations in QCD predict geometric scaling for quark and gluon distribution functions in a large kinematical window, which extends above the saturation scale up to momenta $Q^2$ of order $100 {\rm GeV}^2$. For…

High Energy Physics - Phenomenology · Physics 2014-11-17 E. Iancu , K. Itakura , L. McLerran

We derive a second-order linear differential equation for the leading order gluon distribution function G(x,Q^2) = xg(x,Q^2) which determines G(x,Q^2) directly from the proton structure function F_2^p(x,Q^2). This equation is derived from…

High Energy Physics - Phenomenology · Physics 2010-03-25 Martin M. Block , Loyal Durand , Douglas W. McKay

The effects of the first nonlinear corrections to the DGLAP evolution equations are studied by using the recent HERA data for the structure function $F_2(x,Q^2)$ of the free proton and the parton distributions from CTEQ5L and CTEQ6L as a…

High Energy Physics - Phenomenology · Physics 2014-11-17 K. J. Eskola , H. Honkanen , V. J. Kolhinen , Jianwei Qiu , C. A. Salgado

We review small $x$ contributions to perturbative evolution equations for parton distributions, and their resummation. We emphasize in particular the resummation technique recently developed in order to deal with the apparent instability of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Guido Altarelli , Richard D. Ball , Stefano Forte

Power-suppressed corrections to parton evolution may affect the theoretical accuracy of current determinations of parton distributions. We study the role of multigluon-exchange terms in the extraction of the gluon distribution for the Large…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. Hautmann

We consider deep inelastic scattering off nuclei in the Regge limit within the Glauber-Gribov model. Using unitarized parton distribution functions for the proton, we find sizeable shadowing effects on the nuclear total and longitudinal…

High Energy Physics - Phenomenology · Physics 2014-11-20 Nestor Armesto , Alexei B. Kaidalov , Carlos A. Salgado , Konrad Tywoniuk

We investigate the impact of so called kinematic constraint on gluon evolution at small $x$. Implanting the constraint on the real emission term of gluon ladder diagram, we obtain an integro-differential form of BFKL equation. Later we…

High Energy Physics - Phenomenology · Physics 2020-04-22 P. Phukan , M. Lalune , J. K. Sarma

Recent HERA low $Q^2$ data show that the logarithmic slope of the protonstructure function ($\frac{\partial F_2}{\partial \ln Q^2}$) is significantly different from perturbative QCD expectations for smallvalues of $Q^2$ at exeedingly small…

High Energy Physics - Phenomenology · Physics 2019-08-17 E. Gotsman , E. levin , U. Maor

The $F_{2}$ structure functions of the inelastic lepton-hadron scattering is calculated in the case of non-zero intermediate gluon-quarks self-energy $M_{gq}^{2}$ and quasielastic limit. It is shown that in the quasielastic limit the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ya. D. Krivenko-Emetov

Nonsinglet contributions to the $g_1(x,Q^2)$ structure function are calculated in the double-logarithmic approximation of perturbative QCD in the region $x \ll 1$. Double logarithmic contributions of the type $(\alpha_s \ln ^2 (1/x))^k$…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Bartels

It is usually assumed -- following the parton model -- that the leading-twist structure functions measured in deep inelastic lepton-proton scattering are simply the probability distributions for finding quarks and gluons in the target…

High Energy Physics - Phenomenology · Physics 2009-09-11 S. J. Brodsky

In this paper t and x-evolutions of gluon distribution function from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi(DGLAP) evolution equation in leading order(LO) at low-x, assuming the Regge behaviour of quark and gluon at this limit, are…

High Energy Physics - Phenomenology · Physics 2014-11-18 U. Jamil , J. K. Sarma

We introduce a nonperturbative interaction for light-cone fluctuations containing quarks and gluons. The $\bar qq$ interaction squeezes the transverse size of these fluctuations in the photon and one does not need to simulate this effect…

High Energy Physics - Phenomenology · Physics 2011-05-05 B. Z. Kopeliovich , A. Schaefer , A. V. Tarasov

Using Laplace transform techniques, along with newly-developed accurate numerical inverse Laplace transform algorithms, we decouple the solutions for the singlet structure function $F_s(x,Q^2)$ and $G(x,Q^2)$ of the two leading-order…

High Energy Physics - Phenomenology · Physics 2010-04-12 Martin M. Block , Loyal Durand , Phuoc Ha , Douglas W. McKay