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We solve the LO DGLAP QCD evolution equation for truncated Mellin moments of the nucleon nonsinglet structure function. The results are compared with those, obtained in the Chebyshev-polynomial approach for $x$-space solutions. Computations…

High Energy Physics - Phenomenology · Physics 2014-11-18 D. Kotlorz , A. Kotlorz

Within the framework of generalized factorization of higher-twist contributions to semi-inclusive cross section of deeply inelastic scattering off a large nucleus, multiple parton scattering leads to an effective medium-modified…

High Energy Physics - Phenomenology · Physics 2014-11-20 Wei-tian Deng , Xin-Nian Wang

We revisit the evolution of generalised parton distributions (GPDs) in momentum space. We formulate the evolution kernels at one-loop in perturbative QCD (pQCD) in a form suitable for numerical implementation and that allows for an accurate…

High Energy Physics - Phenomenology · Physics 2022-10-12 Valerio Bertone , Hervé Dutrieux , Cédric Mezrag , José M. Morgado , Hervé Moutarde

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 propose a numerical method for approximate calculations of the time evolution of point particle systems given only the system's Hamiltonian function and initial conditions. The method both generates and solves the equations of motion…

Computational Physics · Physics 2022-12-27 José M. L. Amoreira , Luís J. M. Amoreira

Dominant present path for determination of quarks and gluon distribution functions from data is based on pre-assumed form of parameters. Here, an alternative direct, or non-parametric method is spelled out. As the main task, least square…

High Energy Physics - Phenomenology · Physics 2013-09-12 M. Goshtasbpour , M. Zandi

Initial conditions are required to solve medium modified DGLAP (mDGLAP) evolution equations for modified fragmentation functions due to multiple scatterings and parton energy loss. Such initial conditions should in principle include energy…

Nuclear Theory · Physics 2014-03-26 Ning-Bo Chang , Wei-Tian Deng , Xin-Nian Wang

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

We analytically solved the QED $\otimes$ QCD coupled DGLAP evolution equations at leading order (LO) quantum electrodynamics (QED) and next to leading order (NLO) quantum chromodynamics (QCD) approximations, using the Laplace transform…

High Energy Physics - Phenomenology · Physics 2017-07-07 Marzieh Mottaghizadeh , Parvin Eslami , Fatemeh Taghavi-Shahri

We propose a system of evolution equations that describe in-medium time-evolution of transverse-momentum-dependent quark and gluon fragmentation functions. Furthermore, we solve this system of equations using Monte Carlo methods. We then…

High Energy Physics - Phenomenology · Physics 2022-06-07 E. Blanco , K. Kutak , W. Placzek , M. Rohrmoser , K. Tywoniuk

I report on a numerical program for the evolution of parton distributions. The program uses the Mellin-transform method with an optimized contour. Due to this optimized contour the program needs only a few evaluations of the integrand and…

High Energy Physics - Phenomenology · Physics 2009-11-07 Stefan Weinzierl

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

I present a highly efficient method for evolving parton distributions in perturbative QCD. The method allows evolving the parton distribution functions according to any of the commonly-used truncations of the evolution equations (which…

High Energy Physics - Phenomenology · Physics 2014-11-17 David A. Kosower

Based on a sumrule for the nucleon spin we expand quark and gluon orbital angular momentum operators and derive an evolution matrix for higher moments of the corresponding distributions. In combination with the spin-dependent DGLAP-matrix…

High Energy Physics - Phenomenology · Physics 2014-11-17 P. Haegler , A. Schaefer

This document describes a Fortran 95 package for carrying out DGLAP evolution and other common manipulations of parton distribution functions (PDFs). The PDFs are represented on a grid in x-space so as to avoid limitations on the functional…

High Energy Physics - Phenomenology · Physics 2010-03-25 Gavin P. Salam , Juan Rojo

A simple, new method for solving for the $Q^2$ evolution of parton distributions in perturbative QCD using cubic splines is described and applied to the evolution of nonsinglet quark distributions.

Nuclear Theory · Physics 2014-11-18 C. J. Benesh

We show the new relationship [1] between the anomalous dimensions, resummed through next-to-next-to-leading-logarithmic order, in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for the first Mellin moments…

High Energy Physics - Phenomenology · Physics 2018-11-14 Bernd A. Kniehl , Anatoly V. Kotikov

The DG algorithm is a powerful method for solving pdes, especially for evolution equations in conservation form. Since the algorithm involves integration over volume elements, it is not immediately obvious that it will generalize easily to…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Saul A. Teukolsky

Over the past few decades, there has been substantial interest in evolution equations that involving a fractional-order derivative of order $\alpha\in(0,1)$ in time, due to their many successful applications in engineering, physics, biology…

Numerical Analysis · Mathematics 2019-01-30 Bangti Jin , Raytcho Lazarov , Zhi Zhou

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