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We make a critical study of the relationship between the singlet structure function $F_{2}^{S}$ and the gluon distribution $G(x,Q^{2})$ proposed in the past two decades, which is frequently used to extract the gluon distribution from the…

High Energy Physics - Phenomenology · Physics 2014-04-22 G. R. Boroun

We argue that the distribution functions for quarks and gluons are computable at small x for sufficiently large nuclei, perhaps larger than can be physically realized. For such nuclei, we argue that weak coupling methods may be used. We…

High Energy Physics - Phenomenology · Physics 2011-05-05 Larry McLerran , Raju Venugopalan

We obtain an approximate analytical form of the gluon distribution using the GLAP equation with a factorization ansatz,and test its validity by comparing it with that of Gluck,Reya and Vogt at low $x$ regime. We also present calculations of…

High Energy Physics - Phenomenology · Physics 2014-11-17 Ranjita Deka , D. K. Choudhury

We present some simple methods to find gluon distribution from analysis of deuteron F_{2} structure function data at moderately low-x. Here we use the leading order(LO) Altarelli -Parisi(AP) evolution equation and New Muon Collaboration…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. K. Sarma , G. A. Ahmed

We consider a simple model for QCD dynamics in which DGLAP integro-differential equation may be solved analytically. This is a gauge model which possesses dominant evolution of gauge boson (gluon) distribution and in which the gauge…

High Energy Physics - Phenomenology · Physics 2023-04-25 Gustavo Alvarez , Gorazd Cvetic , Bernd A. Kniehl , Igor Kondrashuk , Ivan Parra-Ferrada

We are investigating the behavior of the fragmentation function of a gluon, denoted as $ D_{g}(x,\mu^2)$, where $\mu$ represents the observable scale. This function is derived from the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP)…

High Energy Physics - Phenomenology · Physics 2025-09-25 H. S. Nakhaei , G. R. Boroun

The small $x$ behaviour of the structure function $h_1(x,Q^2)$ is studied within the leading logarithmic approximation of perturbative QCD. There are two contributions relevant at small $x$. The leading one behaves like $(\frac{1}{x})^0$…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Kirschner , L. Mankiewicz , A. Schäfer , L. Szymanowski

In this work we have suggested a solution of the Gribov-Levin-Ryskin-Mueller-Qiu (GLR-MQ) nonlinear evolution equation at next-to-next-to-leading order (NNLO). The range of $Q^2$ in which we have solved the GLR-MQ equation is Regge region…

High Energy Physics - Phenomenology · Physics 2018-01-22 P. Phukan , M. Lalung , J. K. Sarma

We present for first time the computation at large $q_T$ (or small $b_T$) matching coefficients of Transverse Momentum Dependent Parton Distribution Function (TMDPDF) for linearly polarised to the integrated gluon distribution at…

High Energy Physics - Phenomenology · Physics 2019-08-19 Daniel Gutierrez-Reyes , Sergio Leal Gómez , Ignazio Scimemi , Alexey Vladimirov

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…

High Energy Physics - Phenomenology · Physics 2019-05-13 B. Rezaei , G. R. Boroun

We present numerical solutions of the $Q^2$ evolution equations at next-to-leading order (NLO) for unpolarized and polarized parton distributions, in both the flavor non-singlet and singlet channels. The numerical method is based on a…

High Energy Physics - Phenomenology · Physics 2009-10-28 T. Weigl , W. Melnitchouk

I investigate the relationship between the gluon distribution obtained using a dipole model fit to low-x data on F_2(x,Q^2) and standard gluons obtained from global fits with the collinear factorization theorem at fixed order. I stress the…

High Energy Physics - Phenomenology · Physics 2014-11-18 R. S. Thorne

We employ relations between spacelike and timelike deep-inelastic processes in perturbative QCD to calculate the next-to-next-to-leading order (NNLO) contributions to the timelike quark-quark and gluon-gluon splitting functions for the…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Moch , A. Vogt

We computed the longitudinal proton structure function $F_{L}$, using the nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-parisi (NLDGLAP) evolution equation approach at small $x$. For the gluon distribution, the nonlinear effects are related…

High Energy Physics - Phenomenology · Physics 2014-02-07 G. R. Boroun

The computation of observables in high energy QCD involves an average over stochastic semiclassical small-x gluon fields. The weight of various configurations is determined by the effective action. We introduce a method to study…

High Energy Physics - Phenomenology · Physics 2017-10-12 Adrian Dumitru , Vladimir Skokov

We present a study of the contribution of antishadowing effects on the gluon distribution functions $G(x,Q^2)$ in light of the Gribov-Levin-Ryskin-Mueller-Qiu, Zhu-Ruan-Shen (GLR-MQ-ZRS) nonlinear equation at small-$x$, where $x$ is the…

High Energy Physics - Phenomenology · Physics 2019-09-25 M. Lalung , P. Phukan , J. K. Sarma

We have computed the even-N moments N =< 20 of the gluon-gluon splitting function P_{gg} at the fourth order of perturbative QCD via the renormalization of off-shell operator matrix elements. Our results, derived analytically for a general…

High Energy Physics - Phenomenology · Physics 2024-10-11 G. Falcioni , F. Herzog , S. Moch , A. Pelloni , A. Vogt

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

Nuclear parton distribution functions (NPDFs) are determined by global analyses of experimental data on structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross-section ratios \sigma_{DY}^A/\sigma_{DY}^{A'}. The analyses are done in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , T. -H. Nagai

We present an analysis of the current methods of approximate determination of the gluon density $G(x,Q^2)$ at low-$x$ from the scaling violations of the proton structure function $F_2(x,Q^2)$. The gluon density is obtained from DGLAP…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. B. Gay Ducati , Victor P. B. Gonçalves