Large-$N_c$ relations for the electromagnetic N to Delta(1232) transition

Abstract

We examine the large-$N_c$ relations which express the electromagnetic $N$-to-$\Delta$ transition quantities in terms of the electromagnetic properties of the nucleon. These relations are based on the known large-$N_c$ relation between the $N\to \Delta$ electric quadrupole moment and the neutron charge radius, and a newly derived large-$N_c$ relation between the electric quadrupole ($E2$) and Coulomb quadrupole ($C2$) transitions. Extending these relations to finite, but small, momentum transfer we find that the description of the electromagnetic $N\to \Delta$ ratios ($R_{EM}$ and $R_{SM}$) in terms of the nucleon form factors predicts a structure which may be ascribed to the effect of the ``pion cloud''. These relations also provide useful constraints for the $N\to \Delta$ generalized parton distributions.

4 pages, 1 figure; to appear in PRD, Rapid Communications

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Cited by in corpus (32)

• Baryons as relativistic three-quark bound states
• Electroexcitation of nucleon resonances from CLAS data on single pion electroproduction
• Electroexcitation of nucleon resonances
• D-state effects in the electromagnetic N-Delta transition
• Valence quark contribution for the gamma N -> Delta quadrupole transition extracted from lattice QCD
• Nucleon to Delta electromagnetic transition in the Dyson-Schwinger approach
• Two-photon exchange contribution to elastic $e^{-}$-proton scattering: Full dispersive treatment of $\pi N$ states and comparison with data
• Nucleon and gamma N -> Delta lattice form factors in a constituent quark model
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• Electromagnetic Transition Form Factors of Baryon Resonances
• Results from the N* program at JLab
• Electromagnetic Nucleon-to-Delta Transition in Holographic QCD
• Nucleon resonances in Compton scattering
• Peripheral transverse densities of the baryon octet from chiral effective field theory and dispersion analysis
• Electroexcitation of the ${\Delta }^{+}(1232)$ at low momentum transfer
• Improved empirical parametrizations of the ${\gamma }^{\ast }N\to \Delta (1232)$ and ${\gamma }^{\ast }N\to N(1520)$ helicity amplitudes and the Siegert's theorem
• $N^{\ast }$ Form Factors based on a Covariant Quark Model
• Sum rules across the unpolarized Compton processes involving generalized polarizabilities and moments of nucleon structure functions
• Parametrizations of the ${\gamma }^{\ast }N\to \Delta (1232)$ quadrupole form factors and Siegert's theorem
• New low-$Q^2$ measurements of the ${\gamma }^{\ast }N\to \Delta (1232)$ Coulomb quadrupole form factor, pion cloud parametrizations and Siegert's theorem
• Impact of JLab data on the determination of GPDs at zero skewness and new insights from transition form factors $N\to \Delta$
• Light-front representation of chiral dynamics with Delta isobar and large-N_c relations
• Virtual Compton Scattering measurements in the nucleon resonance region
• $\Delta (1232)$-Resonance in the Hydrogen Spectrum
• Theoretical Analysis of the $p\bar{p}\to {\pi }^0{e}^{+}{e}^{-}$ Process within a Regge Framework
• Exploring Baryon Resonances with Transition Generalized Parton Distributions: Status and Perspectives
• Nucleon to $\Delta$ transition form factors and empirical transverse charge densities
• Combined parametrization of the neutron electric form factor and the ${\gamma }^{\ast }N\to \Delta (1232)$ quadrupole form factors
• Ernest Henley and the shape of baryons
• Resonance Contributions to Radiative Corrections in Charged-Current Elastic (Anti)Neutrino-Nucleon Scattering at GeV Energies
• Quark model calculations of transition form factors at high photon virtualities
• Empirical parametrizations of the resonance amplitudes based on the Siegert's theorem