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Considering a fixed-flavor number scheme and based on laplace transdormation, we perform a leading-order and next-to-leading-order QCD analysis which are including world data on polarized structure functions $g_1$ and $g_2$. During our…

High Energy Physics - Phenomenology · Physics 2023-03-28 Hoda Nematollahi , Abolfazl Mirjalili , Shahin Atashbar Tehrani

Parton densities are obtained from a solution of the extended DGLAP-type evolution equation that includes both QCD and electroweak contributions. The equations are solved using the Parton-Branching (PB) approach, and the evolution is…

High Energy Physics - Phenomenology · Physics 2025-11-12 K. Moral Figueroa , E. Gallo , H. Jung , S. Taheri Monfared

An exact expression for the leading-order (LO) gluon distribution function $G(x,Q^2)=xg(x,Q^2)$ from the DGLAP evolution equation for the proton structure function $F_2^{\gamma p}(x,Q^2)$ for deep inelastic $\gamma^* p$ scattering has…

High Energy Physics - Phenomenology · Physics 2010-01-06 Martin M. Block

The QCD structure of the electron is defined and calculated. The leading order splitting functions are extracted, showing an important contribution from $\gamma$-$Z$ interference. Leading logarithmic QCD evolution equations are constructed…

High Energy Physics - Phenomenology · Physics 2009-10-28 Wojciech Slominski , Jerzy Szwed

We present a set of parton distribution functions (PDFs), based on the NNPDF2.3 set, which includes a photon PDF, and QED contributions to parton evolution. We describe the implementation of the combined QCD+QED evolution in the NNPDF…

$Q^2$ evolution of structure functions in the nucleon and nuclei is investigated by using usual DGLAP equations and parton-recombination equations. Calculated results for proton's $F_2$ and for the ratio $F_2^{Ca}/F_2^D$ are compared with…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Miyama

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 present a first QCD analysis of next-to-next-leading-order (NNLO) contributions of the spin-dependent parton distribution functions (PPDFs) in the nucleon and their uncertainties using the Jacobi polynomial approach. Having the NNLO…

High Energy Physics - Phenomenology · Physics 2016-06-24 F. Taghavi Shahri , Hamzeh Khanpour , S. Atashbar Tehrani , Z. Alizadeh Yazdi

Aspects of the QCD parton densities are briefly reviewed, drawing some parallels to the density matrix formulation of quantum mechanics, exemplified by Wigner functions. We elaborate on the solution of their evolution equations using…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alessandro Cafarella , Claudio Coriano' , Marco Guzzi

We present sets of parton distribution functions (PDFs), based on the NNPDF3.0 family, which include the photon PDF from the NNPDF2.3QED sets, and leading-order QED contributions to the DGLAP evolution as implemented in the public code…

High Energy Physics - Phenomenology · Physics 2016-06-29 V. Bertone , S. Carrazza

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 next-to-leading order (NLO) evolution of the parton distribution functions (PDF's) in QCD is the "industry standard" in the lepton-hadron and hadron-hadron collider data analysis. The standard NLO DGLAP evolution is formulated for…

High Energy Physics - Phenomenology · Physics 2009-10-02 S. Jadach , M. Skrzypek

Perturbative solutions for unpolarized QED parton distribution and fragmentation functions are presented explicitly in the next-to-leading logarithmic approximation. The scheme of iterative solution of QED evolution equations is described…

High Energy Physics - Phenomenology · Physics 2023-09-06 A. B. Arbuzov , U. E. Voznaya

New methods of solutions of the DGLAP equation and their implementation through NNLO in QCD are briefly reviewed. We organize the perturbative expansion that describes in $x$-space the evolved parton distributions in terms of scale…

High Energy Physics - Phenomenology · Physics 2008-12-30 Alessandro Cafarella , Claudio Coriano , Marco Guzzi

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

We present particular and unique solutions of singlet and non-singlet Dokshitzer-Gribov-Lipatov- Altarelli-Parisi (DGLAP) evolution equations in next-to-next-to-leading order (NNLO) at low-x. We obtain t-evolutions of deuteron, proton,…

High Energy Physics - Phenomenology · Physics 2010-02-18 Rasna Rajkhowa

We study parton-branching solutions of QCD evolution equations and present a method to construct both collinear and transverse momentum dependent (TMD) parton densities from this approach. We work with next-to-leading-order (NLO) accuracy…

High Energy Physics - Phenomenology · Physics 2018-02-14 F. Hautmann , H. Jung , A. Lelek , V. Radescu , R. Zlebcik

We perform a global parton analysis of deep inelastic and related hard-scattering data, including ${\cal O}(\alpha_{\rm QED})$ corrections to the parton evolution. Although the quality of the fit is essentially unchanged, there are two…

High Energy Physics - Phenomenology · Physics 2010-03-25 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

We present numerical solutions of the $Q^2$ evolution equations at next-to-leading order (NLO) for unpolarized and polarized parton distributions, in both the flavor non-singlet and singlet channels. The numerical method is based on a…

High Energy Physics - Phenomenology · Physics 2009-10-28 T. Weigl , W. Melnitchouk

Coupled DGLAP equations involving singlet quark and gluon distributions are explored by a Taylor expansion as two first order partial differential equations in two variables. The system of equations are then solved by the Lagrange's method…

High Energy Physics - Phenomenology · Physics 2017-01-11 Dilip Kumar Choudhury , Neelakshi Niti Kachari Borah