${\gamma }^{\ast }N\Delta$ Form Factors from a Relativistic Dynamical Model of Pion Electroproduction

Abstract

We obtain the electromagnetic form factors of the $\gamma N\Delta$ transition by analyzing recent pion-electroproduction data using a fully relativistic dynamical model. Special care is taken to satisfy Ward-Takahashi identities for the Born term in the presence of form factors thereby allowing the use of realistic electromagnetic form factors of the nucleon and pion. We parametrize the $Q^2$ dependence of the {\it bare} $\gamma N\Delta$ form factors by a three-parameter form which is consistent with the asymptotic behavior inferred from QCD. The parameters of the bare $\gamma N\Delta$ form factors are the only free parameters of the model and are fitted to the differential cross-section and multipole-analysis data up to $Q^2=4$ (GeV/c)${}^2$ in the $\Delta (1232)$-resonance region. This analysis emphasizes the significance of the pion-cloud effects in the extraction of the resonance parameters.

arXiv comment9 pages, 5 figures, several small corrections, to be published in Phys. Rev. C

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Cited by in corpus (21)

• Electromagnetic excitation of the Delta(1232)-resonance
• $\Delta$ resonance contribution to two-photon exchange in electron-proton scattering
• Chiral Effective-Field Theory in the Delta(1232) Region: Pion Electroproduction on the Nucleon
• Electromagnetic Nucleon-to-Delta Transition in Chiral Effective-Field Theory
• Gauge-invariant approach to meson photoproduction including the final-state interaction
• Di-Electron Bremsstrahlung in Intermediate-Energy pn and Dp Collisions
• Dilepton production in proton-induced reactions at SIS energies with the GiBUU transport model
• Pion photoproduction in a dynamical coupled-channels model
• D-state effects in the electromagnetic N-Delta transition
• A Covariant model for the nucleon and the $\Delta$
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• Light Cone Sum Rules for gamma* N -> Delta Transition Form Factors
• Detailed analysis of two-boson exchange in parity-violating e-p scattering
• Electromagnetic Transition Form Factors of Baryon Resonances
• Electromagnetic Nucleon-to-Delta Transition in Holographic QCD
• Study of nucleon resonances with electromagnetic interactions
• Di-Electrons from Resonances in Nucleon-Nucleon Collisions
• Two-photon-exchange effects in the electro-excitation of the $\Delta$ resonance
• The Delta(1232) Resonance in Chiral Effective Field Theory
• Nuclear coherent ${\pi }^0$ photoproduction with charge-exchange and spin-flip rescattering
• Two-photon physics