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Related papers: Constraints on spin-dependent parton distributions…

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We present new parton distribution functions (PDFs) at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) in perturbative QCD, derived from a comprehensive global QCD analysis of high-precision data sets from combined HERA…

High Energy Physics - Phenomenology · Physics 2024-12-17 Majid Azizi , Maryam Soleymaninia , Hadi Hashamipour , Maral Salajegheh , Hamzeh Khanpour , Ulf-G. Meißner

I review the basics of the collinear factorization theorem applied primarily to deep inelastic scattering (DIS) involving forward parton distributions (PDFs) and the extensions of this theorem for exclusive processes probing non-forward…

High Energy Physics - Phenomenology · Physics 2015-03-20 Lech Szymanowski

We derive relations between transverse momentum dependent distribution functions (TMDs) and the usual parton distribution functions (PDFs) in the 3D covariant parton model, which follow from Lorentz invariance and the assumption of a…

High Energy Physics - Phenomenology · Physics 2011-05-10 A. V. Efremov , P. Schweitzer , O. V. Teryaev , P. Zavada

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 2016-04-20 Florian Lyonnet

The parton distribution functions (PDFs) which characterize the structure of the proton are currently one of the dominant sources of uncertainty in the predictions for most processes measured at the Large Hadron Collider (LHC). Here we…

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

We investigate the polarized parton distribution functions (PDFs) and their uncertainties by using the world data on the spin asymmetry A_1. The uncertainties of the polarized PDFs are estimated by the Hessian method. The up and down…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , N. Saito

We revise the relation between Parton Distribution Functions (PDFs) and matrix elements computable from lattice QCD, focusing on the quasi-Parton Distribution Functions (qPDFs) approach. We exploit the relation between PDFs and qPDFs in the…

High Energy Physics - Phenomenology · Physics 2020-01-08 Krzysztof Cichy , Luigi Del Debbio , Tommaso Giani

In the past year, polarized deep inelastic scattering experiments at CERN and SLAC have obtained structure function measurements off proton, neutron and deuteron targets at a level of precision never before achieved. The measurements can be…

High Energy Physics - Phenomenology · Physics 2010-04-06 T. Gehrmann , W. J. Stirling

The present status of the longitudinal polarized parton densities (PDFs) and the contribution of their first moments to the nucleon spin is discussed. Special attention is paid to the role of higher twist effects in determining the PDFs and…

High Energy Physics - Phenomenology · Physics 2009-08-24 Elliot Leader , Alexander V. Sidorov , Dimiter B. Stamenov

The parton distribution functions (PDFs) are a non-negotiable input to almost all theory predictions at hadron colliders. In this talk, I introduce PDF determination by global analysis and discuss selected topics concerning recent relevant…

High Energy Physics - Phenomenology · Physics 2010-01-25 Graeme Watt

We apply the Lagrange Multiplier method to study the uncertainties of physical predictions due to the uncertainties of parton distribution functions (PDFs), using the cross section for W production at a hadron collider as an archetypal…

High Energy Physics - Phenomenology · Physics 2009-09-25 D. Stump , J. Pumplin , R. Brock , D. Casey , J. Huston , J. Kalk , H. L. Lai , W. K. Tung

We perform the first global QCD analysis of parton distribution functions (PDFs) in the pion, with lattice-QCD data on gluonic pseudo--Ioffe-time distributions fitted simultaneously with experimental Drell-Yan and leading neutron…

High Energy Physics - Phenomenology · Physics 2025-08-04 William Good , Patrick C. Barry , Huey-Wen Lin , W. Melnitchouk , Alex NieMiera , Nobuo Sato

The precise knowledge of parton distribution functions (PDFs) is indispensable to the accurate calculation of hadron-initiated QCD hard scattering observables. Much of our information on PDFs is extracted by comparing deep inelastic…

High Energy Physics - Phenomenology · Physics 2013-10-03 David Westmark

We review strategies to unveil the primordial large-$x$ structure of the nucleons as well as the pion from hard-scattering experiments. Ideas are presented for learning about the $x\to 1$ limit of nonperturbative QCD dynamics at energy…

High Energy Physics - Phenomenology · Physics 2021-08-10 Aurore Courtoy , Pavel M. Nadolsky

We show that the parton distribution functions (PDF) described by the statistical model have very interesting physical properties which help to understand the structure of partons. The role of the quark helicity components is emphasized as…

High Energy Physics - Phenomenology · Physics 2015-09-28 Claude Bourrely

We report recent studies of the Asymmetry Analysis Collaboration (AAC) on polarized parton distribution functions (PDFs). Using the data on the spin symmetry A_1 in deep inelastic lepton scattering, we investigate optimum polarized PDFs.…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Hirai , S. Kumano , N. Saito

We present a high-statistics lattice QCD determination of the valence parton distribution function (PDF) of the pion, with a mass of 300 MeV, using two very fine lattice spacings of $a=0.06$ fm and 0.04 fm. We reconstruct the $x$-dependent…

Parton distribution functions (PDFs) at large $x$ are poorly constrained by high-energy experimental data, but extremely important for probing physics beyond standard model at colliders. We study the calculation of PDFs at large-$x$ through…

High Energy Physics - Phenomenology · Physics 2025-08-05 Xiangdong Ji , Yizhuang Liu , Yushan Su

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
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