Nucleon form factors in a covariant diquark-quark model

Hellstern, G.; Alkofer, Reinhard; Oettel, Martin; Reinhardt, Hugo

doi:10.1016/s0375-9474(97)00514-9

Cited by 63 publications

(129 citation statements)

References 47 publications

(79 reference statements)

Supporting

Mentioning

125

Contrasting

Order By: Relevance

“…However, instead of determining the various ingredients from their own equations, for instance in a rainbow-ladder truncation, one may equally employ model parametrizations for the quark and diquark propagators, amplitudes and photon vertices. Extending early quark-diquark form factor calculations [350,493,494,[498][499][500][501], this is the avenue taken in the QCD-based model developed in Refs. [502] where the parameters were adjusted to reproduce the nucleon and ∆ masses (potentially leaving room for pion cloud effects) and to some extent also their electromagnetic form factors.…”

Section: B Kinematics Andmentioning

confidence: 96%

See 1 more Smart Citation

Baryons as relativistic three-quark bound states

Eichmann

Sanchis-Alepuz

Williams

et al. 2016

Progress in Particle and Nuclear Physics

426

530

View full text Add to dashboard Cite

We review the spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD. The composite nature of baryons results in a rich excitation spectrum, whilst leading to highly non-trivial structural properties explored by the coupling to external (electromagnetic and other) currents. Both present many unsolved problems despite decades of experimental and theoretical research. We discuss the progress in these fields from a theoretical perspective, focusing on nonperturbative QCD as encoded in the functional approach via Dyson-Schwinger and Bethe-Salpeter equations. We give a systematic overview as to how results are obtained in this framework and explain technical connections to lattice QCD. We also discuss the mutual relations to the quark model, which still serves as a reference to distinguish 'expected' from 'unexpected' physics. We confront recent results on the spectrum of non-strange and strange baryons, their form factors and the issues of two-photon processes and Compton scattering determined in the DysonSchwinger framework with those of lattice QCD and the available experimental data. The general aim is to identify the underlying physical mechanisms behind the plethora of observable phenomena in terms of the underlying quark and gluon degrees of freedom.

show abstract

Section: B Kinematics Andmentioning

confidence: 96%

“…to drastically simplified wave functions for the baryon. An alternative strategy that aims at the preservation of such dynamics has been pursued in [302,327,350] for ground-state baryons and very recently also for the Roper [25]. Here one works again with the quark-diquark Bethe-Salpeter equation from Fig.…”

Section: Approximations and Truncationsmentioning

confidence: 99%

Baryons as relativistic three-quark bound states

Eichmann

Sanchis-Alepuz

Williams

et al. 2016

Progress in Particle and Nuclear Physics

426

530

View full text Add to dashboard Cite

show abstract

“…In practice, one may increase the stability of the numerical procedure by taking advantage of η (in order to escape the above-mentioned poles far enough away). This implies that one can find a plateau within the range 0 < η < 1 where the results do not depend on the parameter η [18,22,23]. The resulting complex coupled integral equations are solved by using the algorithm introduced by Oettel et al [22,23] (see also Ref.…”

Section: Appendix: Numerical Methodsmentioning

confidence: 99%

“…In the ladder approximation the quark-quark T -matrix near the pole can be parametrised as [18,23,24]…”

Section: Nucleon Internal Structurementioning

confidence: 99%

See 1 more Smart Citation

The nuclear matter stability in a non-local chiral quark model

Rezaeian

Pirner

2006

Nuclear Physics A

View full text Add to dashboard Cite

We study the stability of the nuclear matter in a non-local Nambu-Jona-Lasinio model. We work out the equation of state in a relativistic Faddeev approach where we take into account the internal structure of nucleon. We show that the binding energy saturates when the nucleon as a composite particle made of quarks is incorporated.After truncation of the two-body channels to the scalar and axial-vector diquarks, a relativistic Faddeev equation for nucleon bound states in medium is solved in the covariant diquark-quark picture. We investigate the nucleon properties in the nuclear medium such as the role of diquarks within the nucleon and the in-medium modification of the nucleon mass and size.PACS numbers: 12.39. Ki,12.39.Fe,21.65.+f,24.85.+p Keywords: Non-local Nambu-Jona-Lasinio model, nuclear matter stability, quark-diquark structure of the nucleon, quark matter

show abstract

A Solution to Coupled Dyson–Schwinger Equations for Gluons and Ghosts in Landau Gauge

1998

View full text Add to dashboard Cite

A truncation scheme for the Dyson Schwinger equations of QCD in Landau gauge is presented which implements the Slavnov Taylor identities for the 3-point vertex functions. Neglecting contributions from 4-point correlations such as the 4-gluon vertex function and irreducible scattering kernels, a closed system of equations for the propagators is obtained. For the pure gauge theory without quarks this system of equations for the propagators of gluons and ghosts is solved in an approximation which allows for an analytic discussion of its solutions in the infrared: The gluon propagator is shown to vanish for small spacelike momenta whereas the ghost propagator is found to be infrared enhanced. The running coupling of the non-perturbative subtraction scheme approaches an infrared stable fixed point at a critical value of the coupling, : c & 9.5. The gluon propagator is shown to have no Lehmann representation. The results for the propagators obtained here compare favorably with recent lattice calculations.1998 Academic Press

show abstract

Nucleon form factors in a covariant diquark-quark model

Cited by 63 publications

References 47 publications

Baryons as relativistic three-quark bound states

Baryons as relativistic three-quark bound states

The nuclear matter stability in a non-local chiral quark model

A Solution to Coupled Dyson–Schwinger Equations for Gluons and Ghosts in Landau Gauge

Contact Info

Product

Resources

About