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Related papers: Geometric scaling and QCD evolution

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We show that the evolution equations in QCD predict geometric scaling for quark and gluon distribution functions in a large kinematical window, which extends above the saturation scale up to momenta $Q^2$ of order $100 {\rm GeV}^2$. For…

High Energy Physics - Phenomenology · Physics 2014-11-17 E. Iancu , K. Itakura , L. McLerran

Saturation and geometrical scaling (GS) of gluon distributions are a consequence of the non-linear evolution equations of QCD. We argue that in pp GS holds for the inelastic cross-section rather than for the multiplicity distributions. We…

High Energy Physics - Phenomenology · Physics 2016-07-15 Michal Praszalowicz

Geometric scaling is a novel scaling phenomenon observed in deep inelastic scattering at small x: the total virtual photon-proton cross section depends upon the two kinematical variables Q^2 and x only via their combination Q^2 R_0^2(x),…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Iancu , K. Itakura , L. McLerran

We study the effects of including a running coupling constant in high-density QCD evolution. For fixed coupling constant, QCD evolution preserves the initial dependence of the saturation momentum $Q_s$ on the nuclear size $A$ and results in…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. L. Albacete , N. Armesto , J. G. Milhano , C. A. Salgado , U. A. Wiedemann

Using a recursive algorithm to solve the renormalization group equations of N=1 QCD (DGLAP), we describe the most general supersymmetric evolution of the parton distributions. The analysis involves the regular DGLAP evolution, a partial…

High Energy Physics - Phenomenology · Physics 2007-05-23 Claudio Coriano

We address a long standing problem concerning the scale behaviour of parton densities in the low $x$, low $Q^2$ domain. We emphasize the important role of absorptive corrections at low $x$ and use knowledge of diffractive deep inelastic…

High Energy Physics - Phenomenology · Physics 2019-01-30 M. R. Pelicer , E. G. de Oliveira , A. D. Martin , M. G. Ryskin

We analize the renormalization group equations of supersymmetric QCD with N=1 for the evolution of parton distributions. For this purpose we develope a simple recursive algorithm in x-space to include both regular regions and supersymmetric…

High Energy Physics - Phenomenology · Physics 2014-11-17 Claudio Coriano

We consider modifications of the standard non-linear QCD evolution in an attempt to account for some of the missing ingredients discussed recently, such as correlations, discreteness in gluon emission and Pomeron loops. The evolution is…

High Energy Physics - Phenomenology · Physics 2008-11-26 N. Armesto , J. G. Milhano

A generalization of the leading-order DGLAP evolution at small x is performed for the non-singlet structure function by resumming the leading-order DGLAP anomalous dimension to all orders in the QCD coupling. Explicit expressions are…

High Energy Physics - Phenomenology · Physics 2010-03-25 B. I. Ermolaev , M. Greco , S. I. Troyan

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

DIS data from HERA show a striking regularity as \sigma^{\gamma^* p} is a function of the ratio \tau=Q^2/Q_s^2(x) only. The scaling function shows a break at \tau ~ 1, which has been taken as an indication for saturation. However, besides…

High Energy Physics - Phenomenology · Physics 2014-11-18 Emil Avsar , Gosta Gustafson

We compute the Standard Model scalar coupling ($\lambda$) evolution in a particular QCD resummation scheme, where the QCD coupling becomes infrared finite due to the presence of a dynamically generated gluon mass, leading to the existence…

High Energy Physics - Phenomenology · Physics 2015-06-17 J. D. Gomez , A. A. Natale

Gluon distributions of colliding hadrons saturate as a result of the non-linear evolution equations of QCD. As a consequence there exists the so called saturation momentum, which is related to the gluon density per unit rapidity per…

High Energy Physics - Phenomenology · Physics 2016-05-20 Michal Praszalowicz

We obtain a pair of second order differential equations in two variables $x$ and $t$ from the coupled DGLAP QCD evolution equations at small $x$ using the standard Taylor series expansion method.To that end we keep terms upto $O(x^2 )$.We…

High Energy Physics - Phenomenology · Physics 2016-12-28 Luxmi Machahari , D. K. Choudhury , P. K. Sahariah

We examine the parametrization of the QCD coupling in the Evolution Equations, including DGLAP. Our conclusion is that the well-known parametrization, where the argument of the coupling is k^2_{\perp}/\beta or just k^2_{\perp}, stands only…

High Energy Physics - Phenomenology · Physics 2010-05-12 B. I. Ermolaev , S. I. Troyan

The treatment of the running QCD coupling in evolution equations is discussed. It is shown that the use of the virtuality of ladder (vertical) partons as the scale for QCD coupling in every rung of ladder graphs is an approximation that…

High Energy Physics - Phenomenology · Physics 2010-03-25 B. I. Ermolaev , M. Greco , S. I. Troyan

We determined the saturation exponent of the gluon distribution using the solution of the QCD nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-parisi (NLDGLAP) evolution equation at small $x$. The very small $x$ behavior of the gluon…

High Energy Physics - Phenomenology · Physics 2014-02-06 G. R. Boroun

In this paper we develop the DGLAP evolution for the system of produced gluons in the process of diffractive production in DIS, directly from the evolution equation in Color Glass Condensate approach. We are able to describe the available…

High Energy Physics - Phenomenology · Physics 2018-09-26 Carlos Contreras , Eugene Levin , Rodrigo Meneses , Irina Potashnikova

Using an analytical parameterization for the behavior of the x slope of the structure function F_2 at small x in perturbative QCD, at the leading twist approximation of the Wilson operator product expansion, and applying a flat initial…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. V. Kotikov , G. Parente

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
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