English
Related papers

Related papers: Geometric scaling and QCD evolution

200 papers

We start from the two existing QCD evolution equations for structure functions, the BFKL and DGLAP equations, and discuss the theoretical hints for a unifying picture of the evolution in $x$ and $Q^2.$ The main difficulty is due to the…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Peschanski

In this work we have solved the nonlinear GLR-MQ evolution equation upto next-to-leading order (NLO) by considering NLO terms of the gluon-gluon splitting functions and running coupling constant $\alpha_s(Q^2)$. Here, we have incorporated a…

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

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

In this paper, we solved the coupled Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for singlet and gluon structure functions in leading order (LO) at low-x assuming the Regge behaviour of quark and gluon structure…

High Energy Physics - Phenomenology · Physics 2008-10-22 U. Jamil , J. K. Sarma

We study effects of the running of the coupling in QCD at small Bjorken-x and in particular the ones related to gluon saturation. After introducing the steps taken to the derivation of the next to leading order nonlinear evolution equation,…

High Energy Physics - Phenomenology · Physics 2008-12-19 D. N. Triantafyllopoulos

In this paper we have solved the nonlinear Gribov-Levin-Ryskin-Mueller-Qiu (GLR-MQ) evolution equation for gluon distribution function G(x,Q^2) and studied the effects of the nonlinear GLR-MQ corrections to the Leading Order (LO)…

High Energy Physics - Phenomenology · Physics 2014-02-24 Mayuri Devee , J. K. Sarma

We present numerical studies of the leading non-linear corrections to the DGLAP evolution equations of parton distribution functions (PDFs) resulting from gluon recombination, which reduce the pace of evolution at small momentum fractions…

High Energy Physics - Phenomenology · Physics 2024-06-21 Pit Duwentäster , Vadim Guzey , Ilkka Helenius , Hannu Paukkunen

We present a phenomenological study of the small-x behaviour of gluon distribution function $G(x,Q^2)$ at next-to-leading order (NLO) and next-to-next-to-leading order(NNLO) in light of the nonlinear Gribov-Ryskin-Levin-Mueller-Qiu…

High Energy Physics - Phenomenology · Physics 2019-01-23 M. Lalung , P. Phukan , J. K. Sarma

This contribution presents the running triple-gluon-vertex coupling constant, g_lambda, in Hamiltonians for the gluons that are characterized by the size 1/lambda. The coupling constant is obtained from renormalization group equations for…

High Energy Physics - Theory · Physics 2017-08-23 Stanislaw D. Glazek

We analyze the general nonlinear evolution equations for multi gluon correlators derived in hep-ph/9709432 by restricting ourselves to a double logarithmic region. In this region our evolution equation becomes local in transverse momentum…

High Energy Physics - Phenomenology · Physics 2014-11-17 Jamal Jalilian-Marian , Alex Kovner , Andrei Leonidov , Heribert Weigert

We studied the effects of NLO $Q^2$ evolution of generalized parton distributions (GPDs) using the aligned-jet model for the singlet quark and gluon GPDs at an initial evolution scale. We found that the skewness ratio for quarks is a slow…

High Energy Physics - Phenomenology · Physics 2018-02-14 Hamzeh Khanpour , Muhammad Goharipour , Vadim Guzey

We discuss the distinct approaches for high density QCD (hdQCD) in the asymptotic regime of large values of parton density. We derive the AGL equation for running coupling constant and obtain the asymptotic solution, demonstrating that the…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. B. Gay Ducati , V. P. Gonçalves

The longitudinal structure function in deep inelastic scattering is one of the observables from which the gluon distribution can be unfolded. Consequently, this observable can be used to constrain the QCD dynamics at small $x$. In this work…

High Energy Physics - Phenomenology · Physics 2011-09-13 V. P. Goncalves , M. V. T. Machado

The recently proposed nonlinear evolution equation \cite{Kutak:2013hda} for unintegrated gluon densities valid for large values of the QCD coupling constant $\bar{\alpha} _s$ is presented. In particular we outline its derivation, numerical…

High Energy Physics - Phenomenology · Physics 2014-06-24 Krzysztof Kutak

Using the ``Quality Factor'' (QF) method, we analyse the scaling properties of deep-inelastic processes at HERA and fixed target experiments for x<0.01. We look for scaling formulae of the form sigma(tau), where tau(log Q^2, Y) is a scaling…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guillaume Beuf , Robi Peschanski , Christophe Royon , David Salek

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 compute the gluon distribution in deep inelastic scattering at small x by solving numerically the angular ordering evolution equation. The leading order contribution, obtained by neglecting angular ordering, satisfies the BFKL equation.…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Bottazzi , G. Marchesini , G. P. Salam , M. Scorletti

We present a generalization of the $x$-space $\texttt{Candia}$ algorithm to next-to-next-to-next-to-leading order (N$^3$LO) accuracy in Quantum Chromodynamics (QCD) for solving the DGLAP evolution equations for unpolarized parton densities…

High Energy Physics - Phenomenology · Physics 2026-03-24 Casey Hampson , Marco Guzzi

The parton distributions in the proton are evaluated dynamically using a nonlinear QCD evolution equation - the DGLAP equation with twist-4 (the GLR-MQ-ZSR) corrections - starting from a low scale $\mu^2$, where the nucleon consists of…

High Energy Physics - Phenomenology · Physics 2014-09-11 Xurong Chen , Jianhong Ruan , Rong Wang , Pengming Zhang , Wei Zhu

The quark-gluon plasma (QGP) can be explored in relativistic heavy ion collisions by the jet quenching signature, i.e. by the energy loss of a high energy quark or gluon traversing the plasma. We introduce a novel QCD evolution formalism in…

High Energy Physics - Phenomenology · Physics 2010-03-25 S. Domdey , G. Ingelman , H. J. Pirner , J. Rathsman , J. Stachel , K. Zapp