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Related papers: Parton Distributions for LO Calculations

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A new generation of (unpolarized) dynamical parton distribution functions of the nucleon is determined. After introducing basic elements of perturbative QCD, the dynamical model is discussed and compared with the approach to parton…

High Energy Physics - Phenomenology · Physics 2016-09-08 Pedro Jiménez Delgado

We present a new analysis of parton distributions of the proton. This incorporates a wide range of new data, an improved treatment of heavy flavours and a re-examination of prompt photon production. The new set (MRST) shows systematic…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

We present the MCscales approach for incorporating scale uncertainties in parton distribution functions (PDFs). The new methodology builds on the Monte Carlo sampling for propagating experimental uncertainties into the PDF space that…

High Energy Physics - Phenomenology · Physics 2023-03-27 Zahari Kassabov , Maria Ubiali , Cameron Voisey

Generalized parton distributions provide information on the longitudinal and transverse distribution of partons in the fast moving nucleon. Furthermore, they contain information on the spin structure of the nucleon. First results of a…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Göckeler , T. R. Hemmert , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , W. Schroers

Parton distribution functions are key quantities for us to understand the hadronic structures in high-energy scattering, but they are difficult to calculate from lattice QCD. Recent years have seen fast development of the large-momentum…

High Energy Physics - Phenomenology · Physics 2019-04-29 Yong Zhao

In the large momentum transfer limit, generalized parton distributions can be calculated through a QCD factorization theorem which involves perturbatively-calculable hard kernels and light-cone parton distribution amplitudes of hadrons. We…

High Energy Physics - Phenomenology · Physics 2009-11-10 Pervez Hoodbhoy , Xiangdong Ji , Feng Yuan

We use the recent estimates of NNLO splitting functions, made by van Neerven and Vogt, to perform exploratory fits to deep inelastic and related hard scattering data. We investigate the hierarchy of parton distributions obtained at LO, NLO…

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

We calculated the polarized parton distributions in leading order approximation in QCD from valon model. Polarized structure function of the nucleon are analyzed in the polarized valon model in which a nucleon is assumed to be a bound state…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Atashbar Tehrani , Ali N. Khorramian

We recall the physical features of the parton distributions in the quantum statistical approach of the nucleon. Some predictions from a next-to-leading order QCD analysis are compared to recent experimental results. We also consider their…

High Energy Physics - Phenomenology · Physics 2011-07-26 Jacques Soffer

A simple picture of the constituent quark as a composite system of point-like partons is used to construct the unpolarized and polarized parton distributions by a convolution between constituent quark momentum distributions and constituent…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Scopetta , V. Vento , M. Traini

Using QCD motivated and phenomenological considerations, we construct x- dependent polarized parton distributions, which evolve under GLAP evolution, satisfy DIS data and are within positivity constraints. Each flavor is done separately and…

High Energy Physics - Phenomenology · Physics 2014-11-17 Lionel E. Gordon , Mehrdad Goshtasbpour , Gordon P. Ramsey

The formulas directly connecting parton distribution functions (PDFs) at the leading (LO) and the next to leading (NLO) QCD orders are applied to both unpolarized and polarized valence PDFs and produce improved LO results on these…

High Energy Physics - Phenomenology · Physics 2014-03-11 O. Yu. Shevchenko , R. R. Akhunzyanov

An NLO photon parton parametrization is presented based on the existing $F_2^\gamma$ measurements from $e^+e^-$ data and the low-$x$ proton structure function from $ep$ interactions. Also included in the extraction of the NLO parton…

High Energy Physics - Phenomenology · Physics 2009-01-07 W. Slominski , H. Abramowicz , A. Levy

After an introduction to event generators we give an overview of developments in the field of joining matrix elements with parton showers. Starting with matrix element corrections, we also discuss implementations that match LO and NLO…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Gieseke

We present a consistent calculation of the structure functions within a light-front constituent quark model of the nucleon. Relativistic effects and the relevance of the covariance constraints are analyzed for polarized parton…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Faccioli , F. Cano , M. Traini , V. Vento

I discuss recent developments in the determination of parton distributions from global fits. I concentrate on the errors associated with these parton distributions and with the physical quantities which are determined in terms of them. I…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. S. Thorne

This article is an introduction to parton distribution functions and their generalizations which describe the quark and gluon structure of hadrons, and can be measured in various high-energy scattering processes. We provide the theoretical…

High Energy Physics - Phenomenology · Physics 2026-01-23 Cédric Lorcé , A. Metz , B. Pasquini , P. Schweitzer

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

We present a general method to match fully differential next-to-next-to-leading (NNLO) calculations to parton shower programs. We discuss in detail the perturbative accuracy criteria a complete NNLO+PS matching has to satisfy. Our method is…

High Energy Physics - Phenomenology · Physics 2015-06-17 Simone Alioli , Christian W. Bauer , Calvin Berggren , Frank J. Tackmann , Jonathan R. Walsh , Saba Zuberi

We review our recent paper, where we proved Parton distributions functions (PDFs) to be positive at NLO in the $\overline{MS}$ factorization scheme. We present some additional material that was useful in completing the steps for the actual…

High Energy Physics - Phenomenology · Physics 2021-08-25 Alessandro Candido , Stefano Forte , Felix Hekhorn
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