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Related papers: Gluon distribution at moderately low-x from NMC de…

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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 report global analysis results for polarized parton distribution functions in the nucleon. The optimum distributions are determined by using spin asymmetry data on polarized lepton scattering on proton, neutron, and deuteron. Their…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Hirai , S. Kumano , N. Saito

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 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

A simple model for the gluon structure function at small $x$ is presented, which gives an intuitive picture of the transition between the DGLAP and B FKL regimes.

High Energy Physics - Phenomenology · Physics 2017-08-23 Gösta Gustafson

We calculate the ratio of gluon densities, G^Sn(x)/G^C(x), for 0.01<x<0.1, from the new high statistics data on F_2^Sn/F_2^C taken by the NM Collaboration. For small x, the shadowing in the gluon distribution is about equal to the shadowing…

High Energy Physics - Phenomenology · Physics 2009-10-28 T. Gousset , H. J. Pirner

An exact expression for the leading-order (LO) gluon distribution function $G(x,Q^2)=xg(x,Q^2)$ from the DGLAP evolution equation for the proton structure function $F_2^{\gamma p}(x,Q^2)$ for deep inelastic $\gamma^* p$ scattering has…

High Energy Physics - Phenomenology · Physics 2010-01-06 Martin M. Block

We extend the MRS(A) set of parton distributions, which provides an up-to-date description of the structure of the proton probed by hard interactions, into the region of $Q^2$ below $5\ {\rm GeV}^2$. After physically-motivated…

High Energy Physics - Phenomenology · Physics 2009-10-28 AD Martin , WJ Stirling , RG Roberts

We examine the effect of using an angular ordered evolution equation for the unintegrated gluon distribution at small x.

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Bottazzi

We study inclusive electroproduction on the proton at low $x$ and low $Q^2$ using a soft and a hard Pomeron. The contribution of the soft Pomeron is based on the Stochastic Vacuum Model, in which a nonperturbative dipole-dipole cross…

High Energy Physics - Phenomenology · Physics 2011-09-13 U. D'Alesio , A. Metz , H. J. Pirner

We compute the Parton Distribution Functions (PDFs) of the unpolarised muon for the leptons, the photon, the light quarks, and the gluon. We discuss in detail the issues stemming from the necessity of evaluating the strong coupling constant…

High Energy Physics - Phenomenology · Physics 2023-12-14 Stefano Frixione , Giovanni Stagnitto

We use the unintegrated Parton Density Functions of the gluon obtained from a fit to measurements of the structure functions F2 and F2c at HERA to describe the experimental data for F2b, FL and FL at fixed W.

High Energy Physics - Phenomenology · Physics 2007-06-27 H. Jung , A. V. Kotikov , A. V. Lipatov , N. P. Zotov

It is shown that the previously noted extreme perturbative NNLO/NLO instability of the longitudinal structure function F_L(x,Q^2) is a mere artefact of the commonly utilized `standard' gluon distributions. In particular it is demonstrated…

High Energy Physics - Phenomenology · Physics 2014-11-18 M. Glück , C. Pisano , E. Reya

We derive an equation determining the small-x evolution of the F_2 structure function of a large nucleus which includes all multiple pomeron exchanges in the leading logarithmic approximation using Mueller's dipole model. We show that in…

High Energy Physics - Phenomenology · Physics 2014-11-17 Yuri V. Kovchegov

In a recent Letter entitled "A new numerical method for obtaining gluon distribution functions $G(x,Q^2)=xg(x,Q^2)$, from the proton structure function $F_2^{\gamma p}(x,Q^2)$" [arXiv:0907.4790], we derived an accurate and fast algorithm…

High Energy Physics - Phenomenology · Physics 2014-11-20 Martin M. Block

Nuclear parton distribution functions (NPDFs) are determined by a global analysis of experimental measurements on structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross section ratios \sigma_{DY}^A/\sigma_{DY}^{A'}, and their…

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

An updated next-to-leading order (NLO) QCD analysis of the spin asymmetries A_1^N(x,Q^2) and parton distributions delta f(x,Q^2) in longitudinally polarized deep-inelastic lepton-nucleon scattering is presented within the framework of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Stratmann

The latest measurements of $F_2$ at HERA allow for a {\it combination} of gluon and sea quark distributions at small $x$ that is significantly different from those of existing parton sets. We perform a new global fit to deep-inelastic and…

High Energy Physics - Phenomenology · Physics 2016-09-01 A. D. Martin , R. G. Roberts , W. J. Stirling

We formulate a light-front spectator model for the proton incorporating the gluonic degree of freedom. In this model, at high energy scattering of the proton, the active parton is a gluon and the rest is viewed as a spin-$\frac{1}{2}$…

High Energy Physics - Phenomenology · Physics 2023-07-26 Dipankar Chakrabarti , Poonam Choudhary , Bheemsehan Gurjar , Raj Kishore , Tanmay Maji , Chandan Mondal , Asmita Mukherjee

Different approaches to gluon shadowing at small x are reviewed. Some available results relevant for RHIC and LHC are compared.

High Energy Physics - Phenomenology · Physics 2007-05-23 N. Armesto , C. A. Salgado