Unraveling hadron structure with generalized parton distributions

By A. Belitsky, A. Radyushkin. 2005

792 citations recorded by the source corpus.

Abstract The generalized parton distributions, introduced nearly a decade ago, have emerged as a universal tool to describe hadrons in terms of quark and gluonic degrees of freedom. They combine the features of form factors, parton densities and distribution amplitudes—the functions used for a long time in studies of hadronic structure. Generalized parton distributions are analogous to the phase-space Wigner quasi-probability function of nonrelativistic quantum mechanics which encodes full information on a quantum-mechanical system. We give an extensive review of main achievements in the development of this formalism. We discuss physical interpretation and basic properties of generalized parton distributions, their modeling and QCD evolution in the leading and next-to-leading orders. We describe how these functions enter a wide class of exclusive reactions, such as electro- and photo-production of photons, lepton pairs, or mesons. The theory of these processes requires and implies full control over diverse corrections and thus we outline the progress in handling higher-order and higher-twist effects. We catalogue corresponding results and present diverse techniques for their derivations. Subsequently, we address observables that are sensitive to different characteristics of the nucleon structure in terms of generalized parton distributions. The ultimate goal of the GPD approach is to provide a three-dimensional spatial picture of the nucleon, direct measurement of the quark orbital angular momentum, and various inter- and multi-parton correlations.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/6c8b4ed6bbdc3f89afd3d2508c6d0dd515a053ec

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In Nuclear and High Energy Physics

Citations in the corpus

STUDIES OF NUCLEON RESONANCE STRUCTURE IN EXCLUSIVE MESON ELECTROPRODUCTION (2012, background): “47, 401–515 (2001), arXiv:hep-ph/0106012 [hep-ph] [81] A.”
Generalized parton correlation functions for a spin-0 hadron (2008, background): “In other words, this means that the GPCFs can be considered as mother distributions of GPDs and TMDs [24, 25, 4].”
A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector (2012, methodology): “For properties of all these distributions, see the reviews [55,359,360].”
Parton distributions and lattice-QCD calculations: Toward 3D structure (2020, methodology): “…ξ, and that xj−1 moments of gluon GPDs are even polynomials in ξ (see also Section III.4.3); finally, from the norm of the Hilbert space one obtains positivity constraints, or inequalities between GPDs and the corresponding PDFs (Belitsky and Radyushkin, 2005; Diehl, 2003; Kumericki et al., 2016).”
Elements of a theory for multiparton interactions in QCD (2011, background): “Under the assumption of SU(3) flavor symmetry one can derive similar relations for distributions involving strange quarks [130, 132].”