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We perform a comprehensive new Monte Carlo analysis of high-energy lepton-lepton, lepton-hadron and hadron-hadron scattering data to simultaneously determine parton distribution functions (PDFs) in the proton and parton to hadron…

High Energy Physics - Phenomenology · Physics 2021-10-20 E. Moffat , W. Melnitchouk , T. C. Rogers , N. Sato

We present NNPDF3.0, the first set of parton distribution functions (PDFs) determined with a methodology validated by a closure test. NNPDF3.0 uses a global dataset including HERA-II deep-inelastic inclusive cross-sections, the combined…

We discuss the physical nature of quasi-PDFs, especially the reasons for the strong nonperturbative evolution pattern which they reveal in actual lattice gauge calculations. We argue that quasi-PDFs may be treated as hybrids of PDFs and the…

High Energy Physics - Phenomenology · Physics 2017-11-17 Anatoly Radyushkin

We present a new methodology that is able to yield a simultaneous determination of the Parton Distribution Functions (PDFs) of the proton alongside any set of parameters that determine the theory predictions; whether within the Standard…

High Energy Physics - Phenomenology · Physics 2022-05-12 Shayan Iranipour , Maria Ubiali

Recently the concept of quasi parton distributions (quasi-PDFs) for hadrons has been proposed. Quasi-PDFs are defined through spatial correlation functions and as such can be computed numerically using quantum chromodynamics on a…

High Energy Physics - Phenomenology · Physics 2018-12-26 Shohini Bhattacharya , Christopher Cocuzza , Andreas Metz

The electron, positron, and photon Parton Distribution Functions (PDFs) of the unpolarised electron have recently been computed at the next-to-leading logarithmic accuracy in QED, by adopting the $\overline{\rm MS}$ factorisation scheme. We…

High Energy Physics - Phenomenology · Physics 2021-12-22 Stefano Frixione

A "meta-analysis" is a method for comparison and combination of nonperturbative parton distribution functions (PDFs) in a nucleon obtained with heterogeneous procedures and assumptions. Each input parton distribution set is converted into a…

High Energy Physics - Phenomenology · Physics 2015-06-18 Jun Gao , Pavel Nadolsky

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

We explore connections between two common methods for quantifying the uncertainty in parton distribution functions (PDFs), based on the Hessian error matrix and Monte-Carlo sampling. CT14 parton distributions in the Hessian representation…

High Energy Physics - Phenomenology · Physics 2017-04-05 Tie-Jiun Hou , Jun Gao , Joey Huston , Pavel Nadolsky , Carl Schmidt , Daniel Stump , Bo-Ting Wang , Ke-Ping Xie , Sayipjamal Dulat , Jon Pumplin , C. -P. Yuan

We present MAPPDFpol1.0, a new determination of the helicity-dependent parton distribution functions (PDFs) of the proton from a set of longitudinally polarised inclusive and semi-inclusive deep-inelastic scattering data. The determination…

High Energy Physics - Phenomenology · Physics 2025-04-23 MAP , Collaboration , : , Valerio Bertone , Amedeo Chiefa , Emanuele R. Nocera

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 2014-11-20 Paloma Quiroga-Arias , Jose Guilherme Milhano , Urs Achin Wiedemann

We present the main results of our recent papers, where we derived an analytical solution of the QCD evolution equations for parton distribution functions. The valence and non-singlet quark components satisfy the Gross-Llewellyn-Smith and…

High Energy Physics - Phenomenology · Physics 2025-10-24 A. V. Kotikov , A. V. Lipatov

We review the present status of the determination of parton distribution functions (PDFs) in the light of the precision requirements for the LHC in Run 2 and other future hadron colliders. We provide brief reviews of all currently available…

High Energy Physics - Phenomenology · Physics 2016-09-21 A. Accardi , S. Alekhin , J. Blümlein , M. V. Garzelli , K. Lipka , W. Melnitchouk , S. Moch , R. Placakyte , J. F. Owens , E. Reya , N. Sato , A. Vogt , O. Zenaiev

Parton distribution functions play a pivotal role in hadron collider phenomenology. They are non-perturbative quantities extracted from fits to available data, and their scale dependence is dictated by the DGLAP evolution equations. In this…

High Energy Physics - Phenomenology · Physics 2024-08-08 Salvador A. Ochoa-Oregon , David F. Rentería-Estrada , Roger J. Hernández-Pinto , German F. R. Sborlini , Pia Zurita

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

A robust uncertainty estimate in global analyses of Parton Distribution Functions (PDFs) is essential at the Large Hadron Collider (LHC), especially in view of the high-precision data anticipated by experimentalists in the High-Luminosity…

High Energy Physics - Phenomenology · Physics 2026-04-14 Mark N. Costantini , Luca Mantani , James M. Moore , Maria Ubiali

Parton distribution functions (PDFs) describe the structure of hadrons as composed of quarks and gluons. They are needed to make predictions for short-distance processes in high-energy collisions and are determined by fitting to cross…

High Energy Physics - Phenomenology · Physics 2020-11-11 Karol Kovarik , Pavel M. Nadolsky , Davison E. Soper

The computation of the parton distribution functions (PDF) or distribution amplitudes (DA) of hadrons from first principles lattice QCD constitutes a central open problem. In this study, we present and evaluate the efficiency of a selection…

High Energy Physics - Lattice · Physics 2019-05-01 Joseph Karpie , Kostas Orginos , Alexander Rothkopf , Savvas Zafeiropoulos

An overwhelming number of theoretical predictions for hadron colliders require parton distribution functions (PDFs), which are an important ingredient of theory infrastructure for the next generation of high-energy experiments. This…

Lattice QCD offers the possibility of computing parton distributions from first principles, although not in the usual $\overline{MS}$ factorization scheme. We study in this paper the evolution of non-singlet parton distribution functions…

High Energy Physics - Lattice · Physics 2023-11-01 H. Dutrieux , J. Karpie , C. Monahan , K. Orginos , S. Zafeiropoulos