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Related papers: A covariant view on the nucleons' quark core

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We report the first study of the nucleon where the full Poincare-covariant structure of the three-quark amplitude is implemented in the Faddeev equation. We employ an interaction kernel which is consistent with contemporary studies of meson…

High Energy Physics - Phenomenology · Physics 2014-07-24 G. Eichmann , R. Alkofer , A. Krassnigg , D. Nicmorus

A Poincare' covariant Faddeev equation, which describes baryons as composites of confined-quarks and -nonpointlike-diquarks, is solved to obtain masses and Faddeev amplitudes for the nucleon and Delta. The amplitudes are a component of a…

Nuclear Theory · Physics 2010-03-04 R. Alkofer , A. Hoell , M. Kloker , A. Krassnigg , C. D. Roberts

We provide details on a recent solution of the nucleon's covariant Faddeev equation in an explicit three-quark approach. The full Poincare-covariant structure of the three-quark amplitude is implemented through an orthogonal basis obtained…

High Energy Physics - Phenomenology · Physics 2010-04-30 G. Eichmann , R. Alkofer , A. Krassnigg , D. Nicmorus

We compute the electromagnetic form factors of the nucleon in the Poincare-covariant Faddeev framework based on the Dyson-Schwinger equations of QCD. The general expression for a baryon's electromagnetic current in terms of three…

High Energy Physics - Phenomenology · Physics 2011-08-08 Gernot Eichmann

We examine the nucleon's electromagnetic form factors in a Poincare-covariant Faddeev framework. The three-quark core contributions to the form factors are obtained by employing a quark-diquark approximation. We implement the…

High Energy Physics - Phenomenology · Physics 2015-05-20 G. Eichmann , R. Alkofer , C. S. Fischer , A. Krassnigg , D. Nicmorus

A dressed-quark core contribution to nucleon electromagnetic form factors is calculated. It is defined by the solution of a Poincare' covariant Faddeev equation in which dressed-quarks provide the elementary degree of freedom and…

Nuclear Theory · Physics 2010-03-04 I. C. Cloet , G. Eichmann , B. El-Bennich , T. Klahn , C. D. Roberts

We present a calculation of the three-quark core contribution to the mass of the Delta-baryon in a Poincare-covariant Faddeev framework. A consistent setup for the dressed-quark propagator, the quark-quark and quark-diquark interactions is…

High Energy Physics - Phenomenology · Physics 2009-06-25 D. Nicmorus , G. Eichmann , A. Krassnigg , R. Alkofer

A Poincare' covariant Faddeev equation is presented, which enables the simultaneous prediction of meson and baryon observables using the leading-order in a truncation of the Dyson-Schwinger equations that can systematically be improved. The…

Nuclear Theory · Physics 2010-04-15 G. Eichmann , I. C. Cloet , R. Alkofer , A. Krassnigg , C. D. Roberts

A calculation of the current-quark-mass-dependence of nucleon static electromagnetic properties is necessary in order to use observational data as a means to place constraints on the variation of Nature's fundamental parameters. A Poincare'…

Nuclear Theory · Physics 2009-08-18 I. C. Cloet , G. Eichmann , V. V. Flambaum , C. D. Roberts , M. S. Bhagwat , A. Holl

In treating the relativistic three-quark problem, a dressed-quark propagator parameterization is used which is compatible with recent lattice data and pion observables. Furthermore two-quark correlations are modeled as a series of quark…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Oettel , R. Alkofer

The electromagnetic and gravitational form factors of the nucleon are studied simultaneously using a covariant quark-diquark approach, and the pion cloud effect on the form factors is explicitly discussed. In this study, the electromagnetic…

High Energy Physics - Phenomenology · Physics 2025-08-14 Jiaqi Wang , Dongyan Fu , Yubing Dong

The nucleon is described as a bound state of a quark and an extended diquark. Hereby the notion ``diquark'' refers to the modelling of separable correlations in the two-quark Green's functions. Binding of quarks and diquarks takes place via…

High Energy Physics - Phenomenology · Physics 2017-08-23 R. Alkofer , M. Oettel

Electron scattering at large Q^2 probes a nucleon's quark core. This core's contribution to electromagnetic form factors may be calculated using Poincare' covariant Faddeev amplitudes combined with a nucleon-photon vertex that automatically…

Nuclear Theory · Physics 2008-11-26 A Hoell , R. Alkofer , M. Kloker , A. Krassnigg , C. D. Roberts , S. V. Wright

We outline a microscopic framework to calculate nucleon Compton scattering from the level of quarks and gluons within the covariant Faddeev approach. We explain the connection with hadronic expansions of the Compton scattering amplitude and…

High Energy Physics - Phenomenology · Physics 2016-03-23 Gernot Eichmann

We present a calculation of the three-quark core contribution to the mass of the Delta-baryon in a Poincare-covariant Faddeev framework. A consistent setup for the dressed-quark propagator, the quark-quark and quark-diquark interactions is…

High Energy Physics - Phenomenology · Physics 2009-11-06 D. Nicmorus , G. Eichmann , A. Krassnigg , R. Alkofer

Poincare' covariant Faddeev equations for the nucleon and Delta are solved to illustrate that an internally consistent description in terms of confined-quark and nonpointlike confined-diquark-correlations can be obtained. pi N-loop induced…

Nuclear Theory · Physics 2010-02-17 M. B. Hecht , M. Oettel , C. D. Roberts , S. M. Schmidt , P. C. Tandy , A. W. Thomas

We study the mass of a nucleon in a nucleus using a model recently introduced for a nucleon current with a pion cloud component. The method of QCD sum rules is used to determine the mass shifts for nucleons to first order in nuclear density…

Nuclear Theory · Physics 2007-05-23 Andrew J. Harey , Leonard S. Kisslinger

The proton's elastic electromagnetic form factors are calculated using an Ansatz for the nucleon's Poincare' covariant Faddeev amplitude that only retains scalar diquark correlations. A spectator approximation is employed for the current.…

Nuclear Theory · Physics 2009-01-14 J. C. R. Bloch , A. Krassnigg , C. D. Roberts

The nucleon distribution amplitudes and the nucleon-to-pion transition distribution amplitudes are investigated at leading twist within the frame of a light-cone quark model. The distribution amplitudes probe the three-quark component of…

High Energy Physics - Phenomenology · Physics 2010-05-28 B. Pasquini , M. Pincetti , S. Boffi

Electromagnetic form factors of the nucleon in the space-like region are investigated within the framework of a covariant and confining Nambu-Jona-Lasinio model. The bound state amplitude of the nucleon is obtained as the solution of a…

Nuclear Theory · Physics 2014-10-15 Ian C. Cloët , Wolfgang Bentz , Anthony W. Thomas
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