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Related papers: Parton distribution functions from the precise NNL…

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We present three new sets of next-to-leading order parton distribution functions (PDFs) determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed…

High Energy Physics - Phenomenology · Physics 2013-05-15 J. F. Owens , A. Accardi , W. Melnitchouk

A novel method to extract the QCD coupling alpha_s from the energy evolution of the moments of the parton-to-hadron fragmentation functions at low fractional hadron momentum z, is presented. The evolution of the moments (multiplicity, peak,…

High Energy Physics - Phenomenology · Physics 2014-08-14 David d'Enterria , and Redamy Perez-Ramos

In this paper, we present {\tt SMKA18} analysis which is a first attempt to extract the set of next-to-next-leading-order (NNLO) spin-dependent parton distribution functions (spin-dependent PDFs) and their uncertainties determined through…

High Energy Physics - Phenomenology · Physics 2018-05-09 Maral Salajegheh , S. Mohammad Moosavi Nejad , Hamzeh Khanpour , S. Atashbar Tehrani

We present next-to-next-to-leading order (NNLO) parton distribution functions (PDFs) from the CTEQ-TEA group. The CT10NNLO PDF fit is based on essentially the same global data sets used in the CT10 and CT10W NLO PDF analyses. After…

High Energy Physics - Phenomenology · Physics 2014-08-21 Jun Gao , Marco Guzzi , Joey Huston , Hung-Liang Lai , Zhao Li , Pavel Nadolsky , Jon Pumplin , Daniel Stump , 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 2014-11-20 Paloma Quiroga-Arias , Jose Guilherme Milhano , Urs Achin Wiedemann

In this talk, we present our recent next-to-leading order (NLO) nuclear parton distribution functions (nPDFs), which we call EPS09. As an extension to earlier NLO analyses, we supplement the deep inelastic scattering and Drell-Yan dilepton…

High Energy Physics - Phenomenology · Physics 2009-11-18 Kari J. Eskola , Hannu Paukkunen , Carlos A. Salgado

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…

The quark exchange model (QEM) is reformulated for the $A=12$ and $14$ systems to obtain the constituent quark distributions of $^{12}C$ and $^{14}N$ nuclei, respectively. Afterwards, the different types of the point-like parton…

Nuclear Theory · Physics 2021-08-09 A. Hadian , M. Modarres

We determine the uncertainty on the strong coupling alpha_S due to the experimental errors on the data fitted in global analysis of hard-scattering data, within the standard framework of leading-twist fixed-order collinear factorisation in…

High Energy Physics - Phenomenology · Physics 2009-11-22 A. D. Martin , W. J. Stirling , R. S. Thorne , G. Watt

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

We study parton-branching solutions of QCD evolution equations and present a method to construct both collinear and transverse momentum dependent (TMD) parton densities from this approach. We work with next-to-leading-order (NLO) accuracy…

High Energy Physics - Phenomenology · Physics 2018-02-14 F. Hautmann , H. Jung , A. Lelek , V. Radescu , R. Zlebcik

We present a global fit of parton distributions at next-to-next-to-leading order (NNLO) in QCD. The fit is based on the world data for deep-inelastic scattering, fixed-target data for the Drell-Yan process and includes, for the first time,…

High Energy Physics - Phenomenology · Physics 2014-04-02 S. Alekhin , J. Bluemlein , S. Moch

We present a model-independent determination of the nuclear parton distribution functions (nPDFs) using machine learning methods and Monte Carlo techniques based on the NNPDF framework. The neutral-current deep-inelastic nuclear structure…

High Energy Physics - Phenomenology · Physics 2020-10-28 Rabah Abdul Khalek , Jacob J. Ethier , Juan Rojo , Gijs van Weelden

We investigate the uncertainty in the value of the strong coupling $\alpha_S(M_Z^2)$ when allowing it to be a free parameter in the recent MMHT global analyses of deep-inelastic and related hard scattering data that was undertaken to…

High Energy Physics - Phenomenology · Physics 2015-10-28 L. A. Harland-Lang , A. D. Martin , P. Motylinski , R. S. Thorne

We give a brief review of our recent QCD analysis carried out over the deep inelastic scattering data on F2 structure function and in the non-singlet approximation to the accuracy up to next-to-next-to-leading-order. Specifically, analysis…

High Energy Physics - Phenomenology · Physics 2010-08-05 A. V. Kotikov , V. G. Krivokhizhin , B. G. Shaikhatdenov , G. Parente

The formulas directly connecting parton distribution functions (PDFs) and fragmentation functions (FFs) at the next to leading order (NLO) QCD with the same quantities at the leading order (LO) are derived. These formulas are universal,…

High Energy Physics - Phenomenology · Physics 2013-06-12 O. Yu. Shevchenko

The LHC has recently released precise measurements of the transverse momentum distribution of the Z-boson that provide a unique constraint on the structure of the proton. Theoretical developments now allow the prediction of these…

High Energy Physics - Phenomenology · Physics 2017-09-13 Radja Boughezal , Alberto Guffanti , Frank Petriello , Maria Ubiali

We present a comparative study of the invariant mass and rapidity distributions in Drell-Yan lepton pair production, with particular emphasis on the role played by the QCD evolution. We focus our study around the Z resonance ($50 <Q < 200$…

High Energy Physics - Phenomenology · Physics 2010-10-27 Alessandro Cafarella , Claudio Coriano , Marco Guzzi

We study the global analysis for parton distributions as a function of the QCD strong coupling strength alpha_s, and present a new series of distributions that span the range 0.110 < alpha_s(m_Z) < 0.128. We use these distributions to…

High Energy Physics - Phenomenology · Physics 2009-11-11 J. Pumplin , A. Belyaev , J. Huston , D. Stump , W. K. Tung

The choice of data that enters a global QCD analysis can have a substantial impact on the resulting parton distributions and their predictions for collider observables. One of the main reasons for this has to do with the possible presence…

High Energy Physics - Phenomenology · Physics 2014-09-11 Juan Rojo