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We have presented the results of our next-to-next-to-leading order (NNLO) QCD analysis of nuclear parton distribution functions (nuclear PDFs) [Phys. Rev. D 93 (2016) 014026, arXiv:1601.00939 [hep-ph]] using all available neutral current…

High Energy Physics - Phenomenology · Physics 2020-12-17 S. Atashbar Tehrani

The parton distribution functions (PDFs) of the proton, a necessary input to almost all theory predictions for hadron colliders, are reviewed in this document. An introduction to the PDF determination by global analyses of the main PDF…

High Energy Physics - Phenomenology · Physics 2019-08-14 Ringaile Placakyte

The recent global analyses of the nuclear parton distribution functions (nPDFs) lend support to the validity of the factorization theorem of QCD in high-energy processes involving bound nucleons. With a special attention on our latest…

High Energy Physics - Phenomenology · Physics 2011-04-22 Hannu Paukkunen , Carlos A. Salgado , Kari J. Eskola

In this proceedings we describe the computational challenges associated to the determination of parton distribution functions (PDFs). We compare the performance of the convolution of the parton distributions with matrix elements using…

High Energy Physics - Phenomenology · Physics 2019-09-25 Stefano Carrazza , Juan Cruz-Martinez , Jesús Urtasun-Elizari , Emilio Villa

Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear…

High Energy Physics - Phenomenology · Physics 2011-07-29 Paloma Quiroga-Arias , Jose Guilherme Milhano , Urs Achim Wiedemann

This document is intended as a study of benchmark cross sections at the LHC (at 7 TeV) at NLO using modern parton distribution functions currently available from the 6 PDF fitting groups that have participated in this exercise. It also…

In global QCD fits of parton distribution functions (PDFs), a large part of the estimated uncertainty on the PDFs originates from the choices of parametric functional forms and fitting methodology. We argue that these types of uncertainties…

High Energy Physics - Phenomenology · Physics 2023-02-21 Aurore Courtoy , Joey Huston , Pavel Nadolsky , Keping Xie , Mengshi Yan , C. -P. Yuan

We review recent progress towards a determination of a set of polarized parton distributions from a global set of deep-inelastic scattering data based on the NNPDF methodology, in analogy with the unpolarized case. This method is designed…

High Energy Physics - Phenomenology · Physics 2010-11-19 J. Rojo , G. Ridolfi , R. D. Ball , V. Bertone , F. Cerutti , L. Del Debbio , S. Forte , A. Guffanti , J. I. Latorre , M. Ubiali

The goal of this study is to find a prescription for defining parton distributions (PDFs) which are most appropriate for use in those codes where only LO matrix elements (MEs) are used, as in many Monte Carlo generators. We describe a…

High Energy Physics - Phenomenology · Physics 2008-07-15 A. Sherstnev , R. S. Thorne

We present the first open-source analysis of parton distribution functions (PDFs) of charged pions using xFitter, an open-source QCD fit framework to facilitate PDF extraction and analyses. Our calculations are implemented at…

We explore the role of parametrizations for nonperturbative QCD functions in global analyses, with a specific application to extending a phenomenological analysis of the parton distribution functions (PDFs) in the charged pion realized in…

High Energy Physics - Phenomenology · Physics 2024-04-17 Lucas Kotz , Aurore Courtoy , Pavel Nadolsky , Fredrick Olness , Maximiliano Ponce-Chavez

Global QCD analyses of nuclear parton distribution functions (nPDFs) have traditionally relied on the Hessian method for uncertainty estimation. However, the inherent Gaussian approximation and reliance on local curvature often prove…

High Energy Physics - Phenomenology · Physics 2026-03-16 N. Derakhshanian , P. Risse , T. Jezo , M. Klasen , K. Kovarik , A. Kusina

We study several sources of theoretical uncertainty in the determination of parton distributions (PDFs) which may affect current PDF sets used for precision physics at the Large Hadron Collider, and explain discrepancies between them. We…

High Energy Physics - Phenomenology · Physics 2013-05-09 The NNPDF Collaboration , Richard D. Ball , Valerio Bertone , Luigi Del Debbio , Stefano Forte , Alberto Guffanti , Juan Rojo , Maria Ubiali

The full exploitation of the increasingly precise LHC measurements is essential in order to reduce the uncertainty of theoretical predictions at hadron colliders. The NNPDF2.3 fit was the first PDF determination including the effect of the…

High Energy Physics - Phenomenology · Physics 2014-07-14 Maria Ubiali

In this talk, we present the results from our recent global reanalysis of nuclear parton distribution functions (nPDFs), where the DGLAP-evolving nPDFs are constrained by nuclear hard process data from deep inelastic $l+A$ scattering (DIS)…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. J. Eskola , V. J. Kolhinen , H. Paukkunen , C. A. Salgado

The Hessian method is widely applied in the global analysis of parton distribution functions (PDFs), which uses a set of orthogonal eigenvectors to give predictions of a physical observable. Its uncertainty is estimated based on the…

High Energy Physics - Phenomenology · Physics 2025-09-12 Wenxiao Zhan , Siqi Yang , Minghui Liu , Liang Han , Daniel Stump , C. -P. Yuan

Parton distribution functions (PDFs) describe universal properties of bound states and allow us to calculate scattering amplitudes in processes with large momentum transfer. Calculating PDFs involves the evaluation of matrix elements with a…

High Energy Physics - Lattice · Physics 2025-02-10 Mari Carmen Bañuls , Krzysztof Cichy , C. -J. David Lin , Manuel Schneider

Nuclear parton distribution functions (nPDFs) can be determined in a global QCD analysis using a wide range of experimental data. In addition to older fixed-target deep inelastic scattering and Drell-Yan (DY) dilepton production data,…

High Energy Physics - Phenomenology · Physics 2022-07-12 Ilkka Helenius , Marina Walt , Werner Vogelsang

We present a new set of parton distributions, NNPDF3.1, which updates NNPDF3.0, the first global set of PDFs determined using a methodology validated by a closure test. The update is motivated by recent progress in methodology and available…

We investigate the behavior of spin-dependent parton distribution functions (PDFs) at large parton momentum fractions x in the context of global QCD analysis. We explore the constraints from existing deep-inelastic scattering data, and from…

High Energy Physics - Phenomenology · Physics 2015-06-19 P. Jimenez-Delgado , H. Avakian , W. Melnitchouk
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