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Related papers: Gluon evolution at low $x$ and the longitudinal st…

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The singlet contribution to the $g_1(x,Q^2)$ structure function is 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 , B. I. Ermolaev , M. G. Ryskin

In this paper the singlet and non-singlet hadron structure functions have been obtained by solving Dokshitzer-Gribov-Lipatov-Alterelli-Parisi (DGLAP) evolution equations in leading order (LO) at the small-x limit. Here we have used a Taylor…

High Energy Physics - Phenomenology · Physics 2007-05-23 R Baishya , R Rajkhowa , J K Sarma

We derive a non-perturbative evolution equation for the gluon propagator in axial gauges based on the framework of Wetterich's formulation of the exact renormalization group. We obtain asymptotic solutions to this equation in the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Klaus Geiger

Aspects of the QCD parton densities are briefly reviewed, drawing some parallels to the density matrix formulation of quantum mechanics, exemplified by Wigner functions. We elaborate on the solution of their evolution equations using…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alessandro Cafarella , Claudio Coriano' , Marco Guzzi

We apply a previously developed scheme to consistently include the improved saturation model for the unintegrated gluon distribution (UGD) in order to evaluate, in the framework of $k_{t}$ factorization, at small $x$ at the next-to-leading…

High Energy Physics - Phenomenology · Physics 2023-08-29 G. R. Boroun

We show that the gluon distribution function for very large nuclei may be computed for small transverse momentum as correlation functions of an ultraviolet finite two dimensional Euclidean field theory. This computation is valid to all…

High Energy Physics - Phenomenology · Physics 2009-10-22 Larry McLerran , Raju Venugopalan

Gluon distributions in real and virtual photons are calculated using evolution equations in the NLO approximation. The quark distributions in the photon determined on the basis of the QCD sum rule approach in ref.[1] are taken as an input.…

High Energy Physics - Phenomenology · Physics 2019-08-17 B. L. Ioffe , A. Oganesian

Gluon, ghost, and quark propagators are computed in the Schwinger-Dyson formalism. The full set of one-loop and two-loop contributions to the gap equations are evaluated for the first time. A new and efficient method for dealing with…

High Energy Physics - Phenomenology · Physics 2014-09-05 Joseph Meyers , Eric S. Swanson

We examine local Lagrangian approximations for the gravitational evolution of the density distribution function. In these approximations, the final density at a Lagrangian point q at a time t is taken to be a function only of t and of the…

Astrophysics · Physics 2015-06-24 Zacharias A. M. Protogeros , Robert J. Scherrer

The parton structure of the nucleon and pion is investigated in an exploratory model that allows one to assess whether the dressing of quarks can, by itself, produce realistic gluon contributions to light-cone momentum fractions,…

Nuclear Theory · Physics 2025-05-02 Peter C. Tandy

The proton's gluon structure function at small x is larger than nowadays is commonly believed

High Energy Physics - Phenomenology · Physics 2014-11-17 P. V. Landshoff

We present an analytic formula to extract the longitudinal structure function in the next- to -leading order of the perturbation theory at low $x$, from the Regge- like behavior of the gluon distribution and the structure function at this…

High Energy Physics - Phenomenology · Physics 2015-06-18 G. R. Boroun

We give a brief overview of the perturbative QCD description of the proton deep-inelastic structure function F2(x, Q2) at small x. We discuss GLAP and BFKL approaches, and then we review progress towards a more unified treatment.

High Energy Physics - Phenomenology · Physics 2008-02-03 A. D. Martin

We present results for the structure function F_L for a gluon target having nonzero transverse momentum square at order \alpha_s. The results of double convolution (with respect to Bjorken variable x and the transverse momentum) of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. V. Kotikov , A. V. Lipatov , N. P. Zotov

In recent years, Fractal Inspired Models of quark and gluon densities at small x have been proposed. In this paper, we investigate longitudinal structure function F-L (x, Q2) within this approach. We make predictions using the QCD based…

High Energy Physics - Phenomenology · Physics 2014-04-28 Akbari Jahan , D. K. Choudhury

We derive the Leading Order DGLAP evolution of gluon distribution function in the target light cone gauge starting from its standard operator definition. The derivation is performed using the background field formalism also employed in the…

High Energy Physics - Phenomenology · Physics 2025-05-28 Tolga Altinoluk , Guillaume Beuf , Jamal Jalilian-Marian

A comparison of the H1 data on the longitudinal structure function, $F_L$, at small $x$ with the predictions from the generalized vector dominance / color dipole picture (GVD/CDP) is presented. Using the set of parameters previously…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Schildknecht , M. Tentyukov

We calculate the gluon structure function of a color dipole in near-light-cone SU(2) lattice QCD as a function of $x_B$. The quark and antiquark are external non-dynamical degrees of freedom which act as sources of the gluon string…

High Energy Physics - Theory · Physics 2013-05-29 D. Grünewald , E. -M. Ilgenfritz , H. J. Pirner

We use results for the structure functions $F_L$ for a gluon target having nonzero transverse momentum square at order $\alpha_s$, obtained in our previous paper, to compare with recent H1 experimental data for $F_L$ at fixwd W values and…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. V. Kotikov , A. V. Lipatov , N. P. Zotov

Parton distributions in the small $x$ region are numerically predicted by using a modified DGLAP equation with the GRV-like input distributions. We find that gluon recombination at twist-4 level obviously suppresses the rapid growth of…

High Energy Physics - Phenomenology · Physics 2014-11-17 Wei Zhu , Jian-hong Ruan , Ji-feng Yang , Zhen-qi Shen