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Related papers: Generalized parton distributions: recent results

200 papers

We investigate the processes leading to phase-space equilibration of parton distributions in nuclear interactions at collider energies. We derive a set of rate equations describing the chemical equilibration of gluons and quarks including…

Nuclear Theory · Physics 2008-11-26 T. S. Biro , E. van Doorn , B. Mueller , M. H. Thoma , X. N. Wang

Since the announcement of the proton spin crisis by the European Muon Collaboration there has been considerable progress in unravelling the distribution of spin and orbital angular momentum within the proton. We review the current status of…

High Energy Physics - Phenomenology · Physics 2009-08-03 A. W. Thomas

We argue that due to Parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions -- the generalized transverse momentum distributions -- that describes the configuration of an…

High Energy Physics - Phenomenology · Physics 2015-06-17 Aurore Courtoy , Gary R. Goldstein , J. Osvaldo Gonzalez Hernandez , Simonetta Liuti , Abha Rajan

I review quark momentum distributions in the nucleon at large momentum fractions x. Particular attention is paid to the impact of nuclear effects in deuterium on the d/u quark distribution ratio as x -> 1. A new global study of parton…

Nuclear Theory · Physics 2014-11-21 W. Melnitchouk

We give a brief overview on the theory and phenomenology of generalized parton distributions (GPDs), including the recently developed framework of single-diffractive hard exclusive process for matching GPDs to experimental observables. We…

High Energy Physics - Phenomenology · Physics 2024-10-24 Jian-Wei Qiu , Zhite Yu

I review recent theoretical results on polarized deep inelastic lepton nucleon scattering. Some specific issues, like $Q^2$ evolution of structure functions, the small $x$ behaviour, and the determination of polarized parton densities, are…

High Energy Physics - Phenomenology · Physics 2007-05-23 Giovanni Ridolfi

A method is described for calculating the Generalized Parton Distributions (GPDs) of spin 1/2 hadrons made of composite constituents, in an Impulse Approximation framework. GPDs are obtained from the convolution between the light cone…

High Energy Physics - Phenomenology · Physics 2008-11-26 Sergio Scopetta

While the total orbital angular momentum (OAM) of a definite quark flavor in a longitudinally-polarized nucleon can be obtained through a sum rule involving twist-two generalized parton distribution (GPDs), its distribution as a function of…

High Energy Physics - Phenomenology · Physics 2013-08-09 Xiangdong Ji , Xiaonu Xiong , Feng Yuan

We review briefly the physical concept of generalized parton distributions and the experimental challenges associated with the corresponding measurements of deep exclusive reactions.The first data obtained at Jefferson Lab for exclusive…

High Energy Physics - Experiment · Physics 2014-11-17 Michel Garçon

A short overview is given on how generalized parton distributions (GPDs) enter in a variety of hard exclusive processes such as deeply virtual Compton scattering (DVCS) and hard meson electroproduction reactions on the nucleon. We firstly…

High Energy Physics - Phenomenology · Physics 2016-09-06 Marc Vanderhaeghen

We show how generalized parton distributions (GPDs) can be determined in the case where hadrons are described in terms of their partonic degrees of freedom through solutions of dynamical equations. We demonstrate our approach on the example…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. N. Kvinikhidze , B. Blankleider

We study the structure of generalized parton distributions in spin 0 nuclei within a microscopic approach for nuclear dynamics. GPDs can be used on one side as tools to unravel the deep inelastic transverse structure of nuclei in terms of…

High Energy Physics - Phenomenology · Physics 2009-11-11 S. Liuti , S. K. Taneja

We perform a global leading-order QCD fit to recent polarized structure function data in order to extract a consistent set of spin-dependent parton distributions. Assuming that there is no significant intrinsic polarization of the quark…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Gehrmann , W. J. Stirling

This talk presents results from the QCDSF-UKQCD collaboration for moments of leading twist generalized parton distributions in two-flavor lattice QCD based on O(a) improved Wilson Fermions. We study helicity independent and helicity flip…

High Energy Physics - Lattice · Physics 2008-11-26 M. Gockeler , Ph. Hagler , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schafer , G. Schierholz , J. M. Zanotti

An approach is described to calculate Generalized Parton Distributions (GPDs) in Constituent Quark Models (CQM). The GPDs are obtained from wave functions to be evaluated in a given CQM. The general relations linking the twist-two GPDs to…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Scopetta , V. Vento

An earlier extraction from the HERMES experiment of the polarization-averaged parton distribution of strange quarks in the nucleon has been reevaluated using final data on the multiplicities of charged kaons in semi-inclusive deep-inelastic…

High Energy Physics - Experiment · Physics 2014-06-16 The HERMES Collaboration , A. Airapetian , N. Akopov , Z. Akopov , E. C. Aschenauer , W. Augustyniak , A. Avetissian , E. Avetisyan , S. Belostotski , H. P. Blok , A. Borissov , V. Bryzgalov , J. Burns , M. Capiluppi , G. P. Capitani , E. Cisbani , G. Ciullo , M. Contalbrigo , P. F. Dalpiaz , W. Deconinck , R. De Leo , E. De Sanctis , M. Diefenthaler , P. Di Nezza , M. Düren , M. Ehrenfried , G. Elbakian , F. Ellinghaus , E. Etzelmüller , L. Felawka , S. Frullani , D. Gabbert , G. Gapienko , V. Gapienko , J. Garay García , F. Garibaldi , G. Gavrilov , V. Gharibyan , F. Giordano , S. Gliske , M. Hartig , D. Hasch , M. Hoek , Y. Holler , I. Hristova , H. E. Jackson , S. Joosten , R. Kaiser , G. Karyan , T. Keri , E. Kinney , A. Kisselev , V. Korotkov , V. Kozlov , P. Kravchenko , V. G. Krivokhijine , L. Lagamba , L. Lapikás , I. Lehmann , P. Lenisa , W. Lorenzon , B. -Q. Ma , D. Mahon , S. I. Manaenkov , Y. Mao , B. Marianski , H. Marukyan , Y. Miyachi , A. Movsisyan , V. Muccifora , M. Murray , A. Mussgiller , Y. Naryshkin , A. Nass , M. Negodaev , W. -D. Nowak , L. L. Pappalardo , R. Perez-Benito , A. Petrosyan , P. E. Reimer , A. R. Reolon , C. Riedl , K. Rith , G. Rosner , A. Rostomyan , J. Rubin , D. Ryckbosch , Y. Salomatin , A. Schäfer , G. Schnell , B. Seitz , T. -A. Shibata , M. Stahl , M. Statera , E. Steffens , J. J. M. Steijger , F. Stinzing , S. Taroian , A. Terkulov , R. Truty , A. Trzcinski , M. Tytgat , Y. Van Haarlem , C. Van Hulse , D. Veretennikov , V. Vikhrov , I. Vilardi , C. Vogel , S. Wang , S. Yaschenko , Z. Ye , S. Yen , B. Zihlmann , P. Zupranski

We discuss the determination of polarized parton distributions from a next-to-leading order analysis of recent experimental data. We extract the first moment of the polarized quark and gluon distribution and assess the corresponding…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefano Forte , Richard D. Ball , Giovanni Ridolfi

A brief overview of the recent activity in the measurement of the elastic electromagnetic proton and neutron form factors is presented. It is discussed how the quality of the data has been greatly improved by performing double polarization…

Nuclear Theory · Physics 2008-11-26 Marc Vanderhaeghen

Spin and transverse momentum dependent parton distributions - Generalized Parton Distributions (GPDs) - are at the interface between the QCD structure of the hadrons and observable quantities. The GPDs are linear superpositions within…

High Energy Physics - Phenomenology · Physics 2015-10-27 Gary R. Goldstein , Simonetta Liuti

Generalized Parton Distributions of the pion are evaluated in chiral quark models with the help of double distributions. As a result the polynomiality conditions are automatically satisfied. In addition, positivity constraints, proper…

High Energy Physics - Phenomenology · Physics 2009-11-13 Wojciech Broniowski , Enrique Ruiz Arriola , Krzysztof Golec-Biernat