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Related papers: The HOPPET NNLO parton evolution package

200 papers

Deep learning hyper-parameter optimization is a tough task. Finding an appropriate network configuration is a key to success, however most of the times this labor is roughly done. In this work we introduce a novel library to tackle this…

Machine Learning · Computer Science 2018-07-11 Andrés Camero , Jamal Toutouh , Enrique Alba

Parton distribution function (PDF) at small $x$ in a fast-moving proton is investigated within an upgraded parton model that includes parton splitting with branching cascades and parton fusion. In the region of moderately small $x$, we…

High Energy Physics - Phenomenology · Physics 2026-02-27 M. L. Nekrasov

Quantitatively connecting properties of parton distribution functions (PDFs, or parton densities) to the theoretical assumptions made within the QCD analyses which produce them has been a longstanding problem in HEP phenomenology. To…

High Energy Physics - Phenomenology · Physics 2024-07-08 Brandon Kriesten , Jonathan Gomprecht , T. J. Hobbs

We present preliminary results on the determination of spin-dependent, or polarised, Parton Distribution Functions (PDFs) from all relevant inclusive polarised DIS data. The analysis is performed within the NNPDF approach, which provides a…

High Energy Physics - Phenomenology · Physics 2012-06-26 Emanuele R. Nocera , Stefano Forte , Giovanni Ridolfi , Juan Rojo

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

To concisely and effectively demonstrate the capabilities of our program transformation system Loo.py, we examine a transformation path from two real-world Fortran subroutines as found in a weather model to a single high-performance…

Programming Languages · Computer Science 2018-10-05 Andreas Klöckner , Lucas C. Wilcox , T. Warburton

With ever-increasing computational demand for deep learning, it is critical to investigate the implications of the numeric representation and precision of DNN model weights and activations on computational efficiency. In this work, we…

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

A modification of the saturation model of deep inelastic scattering at small x which includes the Altarelli-Parisi (DGLAP) evolution is presented. Significant improvement of the description of the structure function F_2 at large Q^2 is…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Bartels , K. Golec-Biernat , H. Kowalski

Parton distribution functions (PDFs) play a central role in calculations for the Large Hadron Collider (LHC). To gain a deeper understanding of the emergence and interplay of constraints on the PDFs in the global QCD analyses, it is…

We present a Mathematica interface for handling the parton distribution functions of the NNDPF Collaboration, available from the NNPDF hepforge website http://nnpdf.hepforge.org/. As a case study we briefly summarise the first PDF set which…

High Energy Physics - Phenomenology · Physics 2015-06-11 Nathan P. Hartland , Emanuele R. Nocera

Document parsing (DP) transforms unstructured or semi-structured documents into structured, machine-readable representations, enabling downstream applications such as knowledge base construction and retrieval-augmented generation (RAG).…

In this talk, I overview the recent progress on the global analysis of nuclear parton distribution functions (nuclear PDFs). After first introducing the contemporary fits, the analysis procedures are quickly recalled and the ambiguities in…

High Energy Physics - Phenomenology · Physics 2018-03-14 Hannu Paukkunen

We present a study of the results obtained combining LO partonic matrix elements with either LO or NLO partons distributions. These are compared to the best prediction using NLO for both matrix elements and parton distributions. The aim is…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Sherstnev , R. S. Thorne

Nuclear parton distributions $f_A(x,Q^2)$ are studied within a framework of the DGLAP evolution. Measurements of $F_2^A/F_2^D$ in deep inelastic $lA$ collisions, and Drell--Yan dilepton cross sections measured in $pA$ collisions are used as…

High Energy Physics - Phenomenology · Physics 2015-06-25 K. J. Eskola , V. J. Kolhinen , P. V. Ruuskanen , C. A. Salgado

We present a comparative study of the invariant mass and rapidity distributions in Drell-Yan lepton pair production, with particular emphasis on the role played by the QCD evolution. We focus our study around the Z resonance ($50 <Q < 200$…

High Energy Physics - Phenomenology · Physics 2010-10-27 Alessandro Cafarella , Claudio Coriano , Marco Guzzi

The forward-backward asymmetry of the Drell-Yan process in dilepton decays at high invariant masses can be used to probe the parton distribution functions at large x. The behavior of three modern PDF sets (CT18NNLO, MSHT20, and NNPDF4.0)…

High Energy Physics - Phenomenology · Physics 2023-08-02 Yao Fu , Raymond Brock , Daniel Hayden , Chien-Peng Yuan

Q^2 evolution equations are important not only for describing hadron reactions in accelerator experiments but also for investigating ultrahigh-energy cosmic rays. The standard ones are called DGLAP evolution equations, which are…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. Kumano , T. -H. Nagai

A precise knowledge of the quark and gluon structure of the proton, encoded by the parton distribution functions (PDFs), is of paramount importance for the interpretation of high-energy processes at present and future lepton-hadron and…

We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology at LO and NNLO in perturbative QCD, thereby generalizing to these orders the NNPDF2.1 NLO parton…