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Related papers: A new evolution equation

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In the high energy regime, the proton structure consists of a very large number of particles called partons (quarks and gluons) that interact with each other, according to the theory of strong interactions, Quantum Chromodynamics (QCD).…

High Energy Physics - Phenomenology · Physics 2018-08-06 Gilvana C. Penedo , Werner K. Sauter

We solve a unified integral equation to obtain the $x, Q_T$ and $Q$ dependence of the gluon distribution of a proton in the small $x$ regime; where $x$ and $Q_T$ are the longitudinal momentum fraction and the transverse momentum of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Kwiecinski , A. D. Martin , P. J. Sutton

QCD evolution equations can be recast in terms of parton branching processes. We present a new numerical solution of the equations. We show that this parton-branching solution can be applied to analyze infrared contributions to evolution,…

High Energy Physics - Phenomenology · Physics 2017-08-23 F. Hautmann , H. Jung , A. Lelek , V. Radescu , R. Zlebcik

Based on a solution of DGLAP evolution equations at small values of Bjorken variable x, a simple analytic approximation for so-called linearly polarized gluon density \tilde{h}_1^{\perp g}(x,k_t^2, Q^2) is obtained at LO of perturbation…

High Energy Physics - Phenomenology · Physics 2023-10-13 N. A. Abdulov , X. Chen , A. V. Kotikov , A. V. Lipatov

We study the unintegrated, or transverse momentum dependent (TMD) gluon distribution obtained from the best description of the LHC data on the inclusive spectra of hadrons produced in the mid-rapidity region and low transverse momenta at…

High Energy Physics - Phenomenology · Physics 2014-01-15 A. V. Lipatov , G. I. Lykasov , N. P. Zotov

We show that it is possible to use hard-Pomeron behavior to the gluon distribution and singlet structure function at low $x$. We derive a second-order independent differential equation for the gluon distribution and the singlet structure…

High Energy Physics - Phenomenology · Physics 2014-02-05 B. Rezaei , G. R. Boroun

We give a complete account of how soft gluon, massless quark, evolution equations in colour space originate, from a factorization into a hard cross section density operator and a soft function encoding measurements and the projection on…

High Energy Physics - Phenomenology · Physics 2023-08-02 Simon Plätzer

We study the small-$x$ evolution equation for the gluon generalized parton distribution (GPD) $E_g$ of the nucleon. It is shown that $E_g$ at vanishing skewness exhibits the Regge behavior identical to the BFKL Pomeron, despite its…

High Energy Physics - Phenomenology · Physics 2022-12-22 Yoshitaka Hatta , Jian Zhou

We compute the distribution functions for gluons at very small x and not too large values of transverse momenta. We extend the McLerran-Venugopalan model by using renormalization group methods to integrate out effects due to those gluons…

High Energy Physics - Phenomenology · Physics 2009-10-28 Jamal Jalilian-Marian , Alex Kovner , Larry McLerran , Heribert Weigert

We derive the effective action of the hard large-x valence charges up to fourth order in their density. Such non-Gaussian weight functionals contribute at leading order in N_c to the connected two-gluon production diagrams which determine…

High Energy Physics - Phenomenology · Physics 2011-08-08 Adrian Dumitru , Jamal Jalilian-Marian , Elena Petreska

We propose to modify the saturation model of Golec-Biernat and Wusthoff by including DGLAP evolution. We find considerable improvement for the total deep inelastic cross section, in particular in the large Q^2 region. The successful…

High Energy Physics - Phenomenology · Physics 2010-03-25 J. Bartels , K. Golec-Biernat , H. Kowalski

We summarize recent progress in the resummation of perturbative evolution at small x. We show that the problem of incorporating BFKL small x logs in GLAP evolution is now completely solved, and that the main effect of small x resummation is…

High Energy Physics - Phenomenology · Physics 2017-08-23 Stefano Forte , Guido Altarelli , Richard D. Ball

We shown the general approach for Q2 evolution of parton densities and fragmentation functions at low x based on the diagonalization. The diagonalization leads to the two components in the Q2 evolution, each of which contains a…

High Energy Physics - Phenomenology · Physics 2015-02-26 Anatoly Kotikov

We use all the available new precise data for deep inelastic and related hard scattering processes to perform NLO global parton analyses. These new data allow an improved determination of partons and, in particular, the inclusion of the…

High Energy Physics - Phenomenology · Physics 2011-03-23 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

We give a simple quantum mechanical formulation of the eikonal propagation approximation, which has been heavily used in recent years in problems involving hadronic interactions at high energy. This provides a unified framework for several…

High Energy Physics - Phenomenology · Physics 2009-11-07 Alex Kovner , Urs Achim Wiedemann

We discuss possible applications of the equations of motion in the generalized Wilson loop space to the phenomenology of the three-dimensional parton distribution functions in the large-$x_B$ approximation. This regime is relevant for…

High Energy Physics - Phenomenology · Physics 2014-01-09 I. O. Cherednikov , T. Mertens , P. Taels , F. F. Van der Veken

We present a set of formulas to extract two second-order independent differential equations for the gluon and singlet distribution functions. Our results extend from the LO up to NNLO DGLAP evolution equations with respect to the…

High Energy Physics - Phenomenology · Physics 2014-02-04 G. R. Boroun , B. Rezaei

We examine the $Q^2$ evolution of gluon polarization in polarized nucleons. As is well known, the evolution of $\alpha_s \Delta G(Q^2)$ is negligible for typical momentum transfer variations found in experimental deep inelastic scattering.…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. J. Pollock

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

We review small $x$ contributions to perturbative evolution equations for parton distributions, and their resummation. We emphasize in particular the resummation technique recently developed in order to deal with the apparent instability of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Guido Altarelli , Richard D. Ball , Stefano Forte