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Related papers: Constraints on gluon evolution at small x

200 papers

We study systematically the sensitivity of the photon structure function data on the gluon contents of the photon, by using the leading order Altarelli--Parisi (AP) equations. Charm quark contribution is studied in the quark parton model…

High Energy Physics - Phenomenology · Physics 2010-03-25 K. Hagiwara , T. Izubuchi , M. Tanaka , I. Watanabe

A next-to-next-to-leading order (NNLO) QCD calculation of gluon distribution function at small-x is presented. The gluon distribution function is explored analytically in the DGLAP approach by a Taylor expansion at small x as two first…

High Energy Physics - Phenomenology · Physics 2018-08-10 Mayuri Devee , J. K. Sarma

In the following article we describe our measurement of the proton structure function $F_2$ and of the gluon momentum density $xg$ in $ep$ collisions with the ZEUS detector at HERA in 1993. The results for $F_2$ confirm our measurement from…

High Energy Physics - Experiment · Physics 2007-05-23 J. I. Fleck

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 present a global analysis of available data on inclusive structure functions measured in electron-proton scattering at small values of Bjorken-x, including the latest data from the combined HERA analysis on reduced cross sections. Our…

High Energy Physics - Phenomenology · Physics 2015-05-28 Paloma Quiroga-Arias , Javier L. Albacete , Nestor Armesto , Jose Guilherme Milhano , Carlos A. Salgado

The conventional and linearly polarized Weizs\"acker-Williams gluon distributions at small x are defined from the two-point function of the gluon field in light-cone gauge. They appear in the cross section for dijet production in deep…

High Energy Physics - Phenomenology · Physics 2018-03-14 Adrian Dumitru , Vladimir Skokov

I present a simplified model for the gluon Green's function governing high-energy QCD dynamics, in arbitrary space-time dimensions. The BFKL integral equation (either with or without running coupling) reduces to a second order differential…

High Energy Physics - Phenomenology · Physics 2009-02-18 Dimitri Colferai

We discuss the angular dependence of the recently proposed transverse momentum dependent quark and gluon diffractive parton distributions at small-$x$. We introduce the difractive versions of the Sivers function and the elliptic gluon…

High Energy Physics - Phenomenology · Physics 2024-03-29 Yoshitaka Hatta , Feng Yuan

The operation of HERA with polarized proton and electron beams will allow to study a wide variety of observables in polarized electron-proton collisions at $\sqrt s=300$ GeV. The physics prospects of this project have been elaborated in…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. De Roeck , T. Gehrmann

We study the structure functions $F_{k}^{b}(x,Q^{2})$ ($k=2, L$) and the reduced cross section $\sigma_{r}^{b}(x,Q^{2})$ for small values of Bjorken$^{,}$s $x$ variable with respect to the hard (Lipatov) pomeron for the gluon distribution…

High Energy Physics - Phenomenology · Physics 2014-06-03 G. R. Boroun

Gluon TMDs can be accessed through the analysis of azimuthal asymmetries for heavy quark pair and dijet production in electron-proton collisions, similarly to the way quark TMDs are commonly extracted from semi-inclusive deep-inelastic…

High Energy Physics - Phenomenology · Physics 2016-12-21 Cristian Pisano , Daniël Boer , Piet J. Mulders , Jian Zhou

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 investigate the effects of gluon number fluctuations on the total $\gamma\gamma$, $\gamma^*\gamma^*$ cross sections and the photon structure function $F_2^\gamma(x,Q^2)$. Considering a model which relates the dipole-dipole and…

High Energy Physics - Phenomenology · Physics 2015-06-05 V. P. Goncalves , J. T. de Santana Amaral

The gluon contributions to $F_L(x,Q^2)$ in ${\cal O}(\alpha_s)$ are calculated taking into account the transverse momentum of the initial state parton. In comparison with collinear factorization $F_L(x,Q^2)$, is not affected at large $x$…

High Energy Physics - Phenomenology · Physics 2009-10-28 Johannes Blümlein

We check the impact of the gluon distribution due to the number of active flavor employed in the calculation of heavy-quark deep-inelastic scattering (DIS) electro-production on the reduced cross section and structure functions determined…

High Energy Physics - Phenomenology · Physics 2021-05-11 G. R. Boroun , B. Rezaei

I review recent results by Fadin,Lipatov and collaborators and by our group,leading to the almost complete calculation of the next-to-leading BFKL kernel,of its eigenvalues,and of the resummed gluon anomalous dimension. Qualitative…

High Energy Physics - Phenomenology · Physics 2007-05-23 Marcello Ciafaloni

In order to probe the dynamics of parton evolution in deep inelastic scattering at small x, high-p_T particles produced centrally in pseudorapidity are studied. In the BFKL mechanism gluon radiation is expected to be more abundant than for…

High Energy Physics - Experiment · Physics 2016-08-31 M. Kuhlen

A leading order determination of the gluon density in the proton has been performed in the fractional momentum range $1.9 \cdot 10^{-3} < x_{g/p} < 0.18$ by measuring multi-jet events from boson-gluon fusion in deep-inelastic scattering…

High Energy Physics - Experiment · Physics 2012-08-27 H1 Collaboration

Using the QCD dipole picture of the hard BFKL Pomeron, we perform a 3 parameter fit analysis of the recent inclusive structure function experimental measurements at small-$x$ and intermediate $Q^2$. As a byproduct, the longitudinal…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Lengyel , M. V. T. Machado

We study how much gluon shadowing can be perturbatively generated through the modified QCD evolution in heavy nuclei. The evolution of small-$x$ gluons is investigated within the semiclassical approximation. The method of characteristics is…

Nuclear Theory · Physics 2010-11-01 K. J. Eskola , Jianwei Qiu , Xin-Nian Wang