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Related papers: Parton Densities at the LHC

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Parton distribution functions (PDFs) are nonperturbative objects defined by nonlocal light-cone correlations. They cannot be computed directly from Quantum Chromodynamics (QCD). Using a standard lattice QCD approach, it is possible to…

High Energy Physics - Phenomenology · Physics 2017-02-08 Alessandro Bacchetta , Marco Radici , Barbara Pasquini , Xiaonu Xiong

We present an updated determination of nuclear parton distributions (nPDFs) from a global NLO QCD analysis of hard processes in fixed-target lepton-nucleus and proton-nucleus together with collider proton-nucleus experiments. In addition to…

High Energy Physics - Phenomenology · Physics 2022-05-27 Rabah Abdul Khalek , Rhorry Gauld , Tommaso Giani , Emanuele R. Nocera , Tanjona R. Rabemananjara , Juan Rojo

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

In the framework of quantum chromodynamics (QCD), parton distribution functions (PDFs) quantify how the momentum and spin of a hadron are divided among its quark and gluon constituents. Two main approaches exist to determine PDFs. The first…

This report summarizes the latest developments in the CTEQ-TEA global analysis of parton distribution functions (PDFs) in the nucleon. The focus is on recent NNLO fits to high-precision LHC data at 8 and 13 TeV, including Drell-Yan, jet,…

High Energy Physics - Phenomenology · Physics 2024-11-26 A. Ablat , A. Courtoy , S. Dulat , M. Guzzi , T. J. Hobbs , T. -J. Hou , J. Huston , K. Mohan , H. -W. Lin , P. Nadolsky , I. Sitiwaldi , K. Xie , M. Yan , C. -P. Yuan

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

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 study the correlation between different sets of parton distributions (PDFs). Specifically, viewing different PDF sets as distinct determinations, generally correlated, of the same underlying physical quantity, we examine the extent to…

High Energy Physics - Phenomenology · Physics 2021-12-09 Richard D. Ball , Stefano Forte , Roy Stegeman

A new and simple statistical approach is performed to calculate the parton distribution functions (PDFs) of the nucleon in terms of light-front kinematic variables. Analytic expressions of x-dependent PDFs are obtained in the whole x…

High Energy Physics - Phenomenology · Physics 2011-04-07 Lijing Shao , Yunhua Zhang , Bo-Qiang Ma

The high-energy tails of charged- and neutral-current Drell-Yan processes provide important constraints on the light quark and anti-quark parton distribution functions (PDFs) in the large-x region. At the same time, short-distance new…

High Energy Physics - Phenomenology · Physics 2021-08-04 Admir Greljo , Shayan Iranipour , Zahari Kassabov , Maeve Madigan , James Moore , Juan Rojo , Maria Ubiali , Cameron Voisey

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

High Energy Physics - Phenomenology · Physics 2016-08-08 Florian Lyonnet , Aleksander Kusina , Tomáš Ježo , Karol Kovařík , Fred Olness , Ingo Schienbein , Ji-Young Yu

Data collected by the LHCb experiment allow proton structure functions to be probed in a kinematic region beyond the reach of other experiments, both at the LHC and further afield. In these proceedings the significant impact of LHCb Run 1…

High Energy Physics - Experiment · Physics 2019-08-13 Daniel Johnson

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 2021-07-14 Ritu Aggarwal

Sets of parton distribution functions (PDFs) of the proton are reported for the leading (LO), next-to-leading (NLO) and next-to-next-to leading order (NNLO) QCD calculations. The parton distribution functions are determined with the…

We present a comprehensive new global QCD analysis of unpolarized parton distribution functions (PDFs) based upon proton, deuteron and $A\!=\!3$ data, including the latest inclusive deep-inelastic scattering (DIS) measurements from…

High Energy Physics - Phenomenology · Physics 2026-05-04 C. Cocuzza , W. Melnitchouk , N. Sato , A. W. Thomas

We present a new set of parton distribution functions (PDFs) based on a fully global dataset and machine learning techniques: NNPDF4.0. We expand the NNPDF3.1 determination with 44 new datasets, mostly from the LHC. We derive a novel…

The results on polarized parton densities (PDFs) obtained using different methods of QCD analysis of the present polarized DIS data are discussed. Their dependence on the method used in the analysis, accounting or not for the kinematic and…

High Energy Physics - Phenomenology · Physics 2009-11-05 Elliot Leader , Aleksander V. Sidorov , Dimiter B. Stamenov

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

I consider the effects of including a variety of new LHC data sets into the MMHT approach for PDF determination. I consider the impact of fitting new LHC and Tevatron data, which leads to clear improvements in some PDF uncertainties. There…

High Energy Physics - Phenomenology · Physics 2017-08-02 R. S. Thorne , L. A. Harland-Lang , A. D. Martin

We show how to account for correlations between theoretical uncertainties incorporated in parton distribution function (PDF) fits, and the theoretical uncertainties in the predictions made using these PDFs. We demonstrate by explicit…

High Energy Physics - Phenomenology · Physics 2021-10-04 Richard D. Ball , Rosalyn L. Pearson