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Related papers: The HOPPET NNLO parton evolution package

200 papers

A brief overview of the global DGLAP analyses of the nuclear parton distribution functions is given. Although all the current global nPDF sets describe $R_{F_2}^A(x,Q^2)$ well in the large-$x$ region where the data exist, variations between…

High Energy Physics - Phenomenology · Physics 2015-06-25 V. J. Kolhinen

In this paper we discuss the effect of the complete leading-order QED corrections to the DGLAP equations in the perturbative evolution of parton distribution functions (PDFs). This requires the extension of the purely QCD DGLAP evolution,…

High Energy Physics - Phenomenology · Physics 2016-01-27 Valerio Bertone , Stefano Carrazza , Davide Pagani , Marco Zaro

We show how the photon input parton distribution function (PDF) may be calculated with good accuracy, and used in an extended DGLAP global parton analysis in which the photon is treated as an additional point-like parton. The uncertainty of…

High Energy Physics - Phenomenology · Physics 2015-06-19 A. D. Martin , M. G. Ryskin

We present PDFFlow, a new software for fast evaluation of parton distribution functions (PDFs) designed for platforms with hardware accelerators. PDFs are essential for the calculation of particle physics observables through Monte Carlo…

High Energy Physics - Phenomenology · Physics 2020-12-16 Marco Rossi , Stefano Carrazza , Juan M. Cruz-Martinez

We present PDFFlow, a new software for fast evaluation of parton distribution functions (PDFs) designed for platforms with hardware accelerators. PDFs are essential for the calculation of particle physics observables through Monte Carlo…

High Energy Physics - Phenomenology · Physics 2021-05-19 Stefano Carrazza , Juan M. Cruz-Martinez , Marco Rossi

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…

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

The DGLAP analyses of the nuclear parton distribution functions (nPDF) based on the global fits to the data are reviewed, and the results from EKS98 and HKM are compared. The usefulness of measuring hard probes in $pA$ collisions, at the…

High Energy Physics - Phenomenology · Physics 2007-05-23 K. J. Eskola , H. Honkanen , V. J. Kolhinen , C. A. Salgado

Study of parton distribution functions (PDFs) has led to a finer cognisance of the structure of partons in hadrons and the proton structure functions in deep inelastic scattering (DIS). PDFs are instrumental in predicting results for most…

High Energy Physics - Phenomenology · Physics 2025-10-02 Akbari Jahan , Diptimonta Neog

We formulate the momentum-space Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for structure functions measurable in deeply inelastic scattering. We construct a six-dimensional basis of structure functions that…

High Energy Physics - Phenomenology · Physics 2025-01-20 Tuomas Lappi , Heikki Mäntysaari , Hannu Paukkunen , Mirja Tevio

We extract polarized parton distribution functions (PPDFs), referred to as "KTA17," together with the highly correlated strong coupling $\alpha_s$ from recent and up-to-date $g_1$ and $g_2$ polarized structure functions world data at…

High Energy Physics - Phenomenology · Physics 2017-04-07 Hamzeh Khanpour , Sara Taheri Monfared , S. Atashbar Tehrani

We study the interface between Regge behavior and DGLAP evolution in a non-perturbative model for the nucleon structure function based on a multipole pomeron exchange. This model provides the input for a subsequent DGLAP evolution that we…

High Energy Physics - Phenomenology · Physics 2014-11-17 L. Csernai , L. Jenkovszky , K. Kontros , A. Lengyel , V. Magas , F. Paccanoni

This paper investigates the crucial role of parton distribution functions (PDFs) in high-energy physics, particularly their impact on the extraction of generalized parton distributions (GPDs) at zero skewness. To this aim, we perform six…

High Energy Physics - Phenomenology · Physics 2026-03-23 The MMGPDs Collaboration , Fatemeh Irani , Muhammad Goharipour , K. Azizi

In this talk, we introduce our recently completed next-to-leading order (NLO) global analysis of the nuclear parton distribution functions (nPDFs) called EPS09 - a higher order successor to the well-known leading-order (LO) analysis EKS98…

High Energy Physics - Phenomenology · Physics 2014-11-18 H. Paukkunen , K. J. Eskola , C. A. Salgado

We present the software framework underlying the NNPDF4.0 global determination of parton distribution functions (PDFs). The code is released under an open source licence and is accompanied by extensive documentation and examples. The code…

The pre-training and fine-tuning paradigm has contributed to a number of breakthroughs in Natural Language Processing (NLP). Instead of directly training on a downstream task, language models are first pre-trained on large datasets with…

Machine Learning · Computer Science 2023-08-01 Vithursan Thangarasa , Abhay Gupta , William Marshall , Tianda Li , Kevin Leong , Dennis DeCoste , Sean Lie , Shreyas Saxena

The parton distributions functions (PDFs) derived from the NNLO QCD analysis of existing light-targets deep-inelastic-scattering data are presented. The NLO and NNLO PDFs are compared in order to analyze perturbative stability of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Alekhin

We present preliminary results for fits of parton distribution functions (PDFs) which include the resummation of small-$x$ logarithms at NLLx accuracy, performed in the NNPDF framework. We observe an improvement in the description of DIS…

High Energy Physics - Phenomenology · Physics 2017-07-07 Luca Rottoli , Marco Bonvini

uPDFevolv2 is a software package designed for evolving collinear and Transverse Momentum Dependent (TMD) parton densities using the DGLAP evolution equation. A comprehensive description of both the theoretical framework and technical…

High Energy Physics - Phenomenology · Physics 2024-07-23 H. Jung , A. Lelek , K. Moral Figueroa , S. Taheri Monfared

Twist-3 collinear parton distribution functions (PDFs) are matrix elements of quark-gluon-quark or three-gluons light-cone operators. They depend on three momentum fraction variables, which are restricted to a hexagon region, and the…

High Energy Physics - Phenomenology · Physics 2024-07-10 Simone Rodini , Lorenzo Rossi , Alexey Vladimirov