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We present the first Monte Carlo based global QCD analysis of spin-averaged and spin-dependent parton distribution functions (PDFs) that includes nucleon isovector matrix elements in coordinate space from lattice QCD. We investigate the…

High Energy Physics - Phenomenology · Physics 2021-01-13 J. Bringewatt , N. Sato , W. Melnitchouk , Jian-Wei Qiu , F. Steffens , M. Constantinou

We determine the uncertainties on observables arising from the errors on the experimental data that are fitted in the global MRST2001 parton analysis. By diagonalizing the error matrix we produce sets of partons suitable for use within the…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

The goal of this study is to determine a set of diffractive parton distribution function (diffractive PDFs) from a QCD analysis of all available and up-to-date diffractive deep inelastic scattering (diffractive DIS) data sets from HERA $ep$…

High Energy Physics - Phenomenology · Physics 2019-04-02 Hamzeh Khanpour

Given a sample of independent and identically distributed random variables, a novel nonparametric maximum entropy method is presented to estimate the underlying continuous univariate probability density function (pdf). Estimates are found…

Probability · Mathematics 2016-06-30 Jenny Farmer , Donald J. Jacobs

We present a comprehensive new global QCD analysis of polarized inclusive deep-inelastic scattering, including the latest high-precision data on longitudinal and transverse polarization asymmetries from Jefferson Lab and elsewhere. The…

High Energy Physics - Phenomenology · Physics 2016-04-13 Nobuo Sato , W. Melnitchouk , S. E. Kuhn , J. J. Ethier , A. Accardi

In collider physics, parton distribution functions (PDFs) play a crucial role in computing theoretical cross sections for scattering reactions. This study explores how different experimental data sets influence extracted PDFs in CTEQ-TEA…

High Energy Physics - Phenomenology · Physics 2024-06-07 Lucas Kotz

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

At large values of x the parton distribution functions (PDFs) of the proton are poorly constrained and there are considerable variations between different global fits. Data at such high x have already been published by the ZEUS…

High Energy Physics - Experiment · Physics 2020-07-01 ZEUS Collaboration

In this article we obtain a new set of nuclear parton distribution functions (nuclear PDFs) at next-to-leading order and next-to-next-to-leading order accuracy in perturbative QCD. The common nuclear deep-inelastic scattering (DIS) data…

High Energy Physics - Phenomenology · Physics 2021-08-17 Hamzeh Khanpour , Maryam Soleymaninia , S. Atashbar Tehrani , Hubert Spiesberger , Vadim Guzey

Hessian PDF reweighting, or "profiling", has become a widely used way to study the impact of a new data set on parton distribution functions (PDFs) with Hessian error sets. The available implementations of this method have resorted to a…

High Energy Physics - Phenomenology · Physics 2019-09-27 Kari J. Eskola , Petja Paakkinen , Hannu Paukkunen

A thorough understanding of the issues surrounding the determination of parton distributions is crucial due to their importance to calculations of LHC observables. However, it is still not fully understood how much of an impact…

High Energy Physics - Phenomenology · Physics 2014-09-16 Christopher S. Deans

We present a new method, based on Gaussian process regression, for reconstructing the continuous $x$-dependence of parton distribution functions (PDFs) from quasi-PDFs computed using lattice QCD. We examine the origin of the unphysical…

High Energy Physics - Lattice · Physics 2020-11-25 Constantia Alexandrou , Giovanni Iannelli , Karl Jansen , Floriano Manigrasso

New experiments to measure neutrinos in the far-forward region at the Large Hadron Collider (LHC) are under design or already in preparation. Two of them, FASER$\nu$ and SND@LHC, are expected to be active during Run 3 and have the potential…

High Energy Physics - Phenomenology · Physics 2022-07-04 Weidong Bai , Milind Diwan , Maria Vittoria Garzelli , Yu Seon Jeong , Fnu Karan Kumar , Mary Hall Reno

We develop in more detail our reweighting method for incorporating new datasets in parton fits based on a Monte Carlo representation of PDFs. After revisiting the derivation of the reweighting formula, we show how to construct an unweighted…

Heavy quark parton distribution functions (PDFs) play an important role in several Standard Model and New Physics processes. Most PDF analyses rely on the assumption that the charm and bottom PDFs are generated perturbatively by gluon…

High Energy Physics - Phenomenology · Physics 2016-08-17 A. Kusina

A new generation of parton distribution functions with increased precision and quantitative estimates of uncertainties is presented. This work significantly extends previous CTEQ and other global analyses on two fronts: (i) a full treatment…

High Energy Physics - Phenomenology · Physics 2011-07-18 J. Pumplin , D. R. Stump , J. Huston , H. L. Lai , P. Nadolsky , W. K. Tung

I explain the current status of parton-distribution-function (PDF) studies and future experimental prospects on their determinations. First, unpolarized PDFs of the nucleon are introduced as a field of precision QCD physics including…

High Energy Physics - Phenomenology · Physics 2018-09-17 S. Kumano

We present the first official release of the nCTEQ nuclear parton distribution functions (nPDFs) with errors. The main addition to the previous nCTEQ PDFs is the introduction of PDF uncertainties based on the Hessian method. Another…

High Energy Physics - Phenomenology · Physics 2016-06-27 A. Kusina

Knowledge of parton distribution functions (PDFs) at large momentum fraction $ x $ is not only important to study the flavor and spin dynamics of quarks in the nucleon, but also to search for signals of new physics at collider experiments.…

High Energy Physics - Phenomenology · Physics 2020-04-22 Muhammad Goharipour , S. Rostami

Probability theory has become the predominant framework for quantifying uncertainty across scientific and engineering disciplines, with a particular focus on measurement and control systems. However, the widespread reliance on simple…