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Related papers: Complete solution of Altarelli-Parisi evolution eq…

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We formulate and numerically solve the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi~(DGLAP) evolution equations at next-to-leading order in perturbation theory directly for a basis of 6 physical, observable structure functions in deeply…

High Energy Physics - Phenomenology · Physics 2025-09-03 Tuomas Lappi , Heikki Mäntysaari , Hannu Paukkunen , Mirja Tevio

We investigate a numerical solution of the flavor-nonsinglet Altarelli-Parisi equation with next-to-leading-order $\alpha_s$ corrections by using Laguerre polynomials. Expanding a structure function (or a quark distribution) and a splitting…

High Energy Physics - Phenomenology · Physics 2014-11-17 R. Kobayashi , M. Konuma , S. Kumano

The coefficients of the nonlinear terms in a modified Altarelli-Parisi evolution equation with parton recombination are determined in the leading logarithmic ($Q^2$) approximation. The results are valid in the whole $x$ region and contain…

High Energy Physics - Phenomenology · Physics 2013-10-03 Wei Zhu , Jianhong Ruan

We provide code to solve the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for the nucleon transversity parton distribution functions (PDFs), which encode nucleon transverse spin structure. Though codes are widely…

High Energy Physics - Phenomenology · Physics 2025-12-18 Congzhou M Sha , Bailing Ma

The QCD evolution of both unpolarized and polarized generalized parton distributions (GPDs) to next-to-leading order (NLO) accuracy is presented, in both the DGLAP and ERBL regions, for two appropriately symmetrized input distributions…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. Freund , M. F. McDermott

The small x behaviour of the non-singlet structure function is studied within the double logarithmic approximation (DLA) of perturbative QCD. Since there is neither $k_T$ nor $\theta$ ordering in the ladder Feynman graphs, the predicted…

High Energy Physics - Phenomenology · Physics 2016-09-01 B. I. Ermolaev , S. I. Manayenkov , M. G. Ryskin

We present a new method to solve in a semianalytical way the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations at NLO order in the x-space. The method allows to construct an evolution operator expressed in form of a rapidly…

High Energy Physics - Phenomenology · Physics 2014-11-17 Pietro Santorelli , Egidio Scrimieri

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 suggest a new procedure for extrapolating the parton distributions from HERA energies to higher energies at THERA and LHC. The procedure suggested consists of two steps: first, we solve the non-linear evolution equation which includes…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. Lublinsky , E. Gotsman , E. Levin , U. Maor

We have investigated the next-to-next-to-leading order (NNLO) corrections to inclusive hadron production in e^+e^- annihilation and the related parton fragmentation distributions, the `time-like' counterparts of the `space-like'…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Mitov , S. Moch , A. Vogt

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 derive an approximation approach to evolution of the longitudinal structure function, by using a Laplace-transform method. We solve the master equation and derive the longitudinal structure function as a function of the initial condition…

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

Deep inelastic scattering (DIS) total cross section data at small-x as measured by the HERA experiments is well described by Balitsky-Kovchegov (BK) evolution in the leading order dipole picture. Recently the full Next-to-Leading Order…

High Energy Physics - Phenomenology · Physics 2020-08-13 G. Beuf , H. Hänninen , T. Lappi , H. Mäntysaari

We investigate numerical solution of Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) Q^2 evolution equations for longitudinally polarized structure functions. Flavor nonsinglet and singlet equations with next-to-leading-order $\alpha_s$…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. Hirai , S. Kumano , M. Miyama

The aim of the present paper is to apply the Laguerre polynomials method for the analytical solution of the Altarelli- Martinelli equation. We use this method of the low $x$ gluon distribution to the longitudinal structure function using…

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

An analytical solution of the QCD evolution equations for the singlet and gluon distribution is presented. We decouple DGLAP evolution equations into the initial conditions by using a Laplace transform method at $N^{n}LO$ analysis. The…

High Energy Physics - Phenomenology · Physics 2019-05-13 B. Rezaei , G. R. Boroun

We present a novel semi-analytical method for parton evolution. It is based on constructing a family of analytic functions spanning $x$-space which is closed under the considered evolution equation. Using these functions as a basis, the…

High Energy Physics - Phenomenology · Physics 2025-01-13 Juliane Haug , Oliver Schüle , Fabian Wunder

We investigate numerical solution of $Q^2$ evolution equations for structure functions in the nucleon and in nuclei. (Dokshitzer-Gribov-Lipatov-)Altarelli-Parisi and Mueller-Qiu evolution equations are solved in a brute-force method.…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. Miyama , S. Kumano

In this paper, we present {\tt SMKA18} analysis which is a first attempt to extract the set of next-to-next-leading-order (NNLO) spin-dependent parton distribution functions (spin-dependent PDFs) and their uncertainties determined through…

High Energy Physics - Phenomenology · Physics 2018-05-09 Maral Salajegheh , S. Mohammad Moosavi Nejad , Hamzeh Khanpour , S. Atashbar Tehrani

We search for deviations from next-to-leading order QCD evolution in HERA structure function data. We compare to data predictions for structure functions in the small x region, obtained by evolving backwards to low Q^2 the results of a…

High Energy Physics - Phenomenology · Physics 2014-11-20 Fabrizio Caola , Stefano Forte , Juan Rojo