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Related papers: Geometric scaling and QCD evolution

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The behavior of the gluon distribution of the proton in the low-$x$, low-$Q^2$ domain of deep inelastic electron-proton scattering (DIS) is being investigated. By considering two-gluon exchange as the dominant interaction in the low-$x$,…

High Energy Physics - Phenomenology · Physics 2026-02-24 G. R. Boroun , M. Kuroda , Dieter Schildknecht

The perturbative QCD predicts that the growth of the gluon density at small-$x$ (high energies) should saturate, forming a Color Glass Condensate (CGC), which is described in mean field approximation by the Balitsky-Kovchegov (BK) equation.…

High Energy Physics - Phenomenology · Physics 2014-11-20 M. A. Betemps , V. P. Goncalves , J. T. de Santana Amaral

We determined the effects of the first nonlinear corrections to the gluon distribution using the solution of the QCD nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (NLDGLAP) evolution equation at small x. By using a Laplace-transform…

High Energy Physics - Phenomenology · Physics 2014-02-05 G. R. Boroun , S. Zarrin

The perturbative QCD expansion for $J/\psi$ photoproduction appears to be unstable: the NLO correction is large (and of opposite sign) to the LO contribution. Moreover, the predictions are very sensitive to the choice of factorization and…

High Energy Physics - Phenomenology · Physics 2016-12-21 S. P. Jones , A. D. Martin , M. G. Ryskin , T. Teubner

The corrections of gluon fusion to the DGLAP and BFKL equations are discussed in a united partonic framework. The resulting nonlinear evolution equations are the well-known GLR-MQ-ZRS equation and a new evolution equation. Using the…

High Energy Physics - Phenomenology · Physics 2016-08-08 Wei Zhu , Zhenqi Shen , Jianhong Ruan

The numerical solutions of the non-linear evolution equation are shown to display the ``geometric'' scaling recently discovered in the experimental data. The phenomena hold both for proton and nucleus targets for all $x$ below $10^{-2}$ and…

High Energy Physics - Phenomenology · Physics 2009-01-07 M. Lublinsky

An approximated solution for gluon distribution from DGLAP evolution equations with NLO splitting function in the small-$x$ limit is presented. We first obtain the simplified forms of LO and NLO splitting functions in the small-$x$ limit.…

High Energy Physics - Phenomenology · Physics 2024-01-29 Jingxuan Chen , Xiaopeng Wang , Yanbing Cai , Xurong Chen , Qian Wang

The DGLAP, BFKL, modified DGLAP and modified BFKL equations are constructed in a unified partonic framework. The antishadowing effect in the recombination process is emphasized, which leads to two different small $x$ behaviors of gluon…

High Energy Physics - Phenomenology · Physics 2007-05-23 Wei Zhu , Zhenqi Shen , Jifeng Yang , Jianhong Ruan

The solution of DGLAP evolution equation for the twist-3 gluon operators is obtained in the Double Logarithmic Approximation of QCD perturbation theory. The method used for the solution is similar to the reggeon field theory. The…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. G. Shuvaev

A modification of the saturation model of deep inelastic scattering at small x which includes the Altarelli-Parisi (DGLAP) evolution is presented. Significant improvement of the description of the structure function F_2 at large Q^2 is…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Bartels , K. Golec-Biernat , H. Kowalski

Using the colour dipole picture for photon-nucleus interactions at small $x$ together with the Color Glass Condensate (CGC) effective theory, we demonstrate that the next-to-leading (NLO) order corrections to the cross-section for the…

High Energy Physics - Phenomenology · Physics 2025-05-05 Paul Caucal , Edmond Iancu

We show that the geometric scaling of the total virtual photon-proton cross section data can be explained using standard linear GLAP perturbative evolution with generic boundary conditions in a wide kinematic region. This allows us to…

High Energy Physics - Phenomenology · Physics 2010-03-25 Fabrizio Caola , Stefano Forte

We propose a systematic approximation scheme for solving GLAP evolution equations at small Bjorken-$x$. The approximate solutions interpolate smoothly between hard (singular as $x^{-(1+\lambda)}$, $\lambda> 0$) and soft (singular at most as…

High Energy Physics - Phenomenology · Physics 2007-05-23 L. Mankiewicz , A. Saalfeld , T. Weigl

Saturation of gluon distribution is a consequence of the non-linear evolution equations of QCD. Saturation implies the existence of so called saturation momentum which is defined as a gluon density per unit rapidity per transverse area. At…

High Energy Physics - Phenomenology · Physics 2015-10-29 Michal Praszalowicz

We propose an evolution equation for unintegrated gluon densities that is valid for large values of the QCD coupling constant $\bar{\alpha} _s$. Our approach is based on the linear resummation model introduced by Sta\'{s}to. We generalize…

High Energy Physics - Phenomenology · Physics 2014-02-04 Krzysztof Kutak , Piotr Surówka

Transverse momentum integrated multiplicities in the central region of pp collisions at LHC energies satisfy Koba-Nielsen-Olesen scaling. We attempt to relate this finding to multiplicity distributions of soft gluons. KNO scaling emerges if…

High Energy Physics - Phenomenology · Physics 2012-09-20 Adrian Dumitru , Elena Petreska

It is known that radial collapse around density peaks can explain the key features of evolution of correlation function in gravitational clustering in three dimensions. The same model also makes specific predictions for two dimensions. In…

Astrophysics · Physics 2009-10-30 J. S. Bagla , S. Engineer , T. Padmanabhan

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

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

We discuss QCD evolution equations for two and three particle correlation functions of quarks and gluon fields in a hadron which describe development of the momentum distribution of a parton system with a change of the wave length of a…

High Energy Physics - Phenomenology · Physics 2017-08-23 A. V. Belitsky