D-state configurations in the electromagnetic form factors of the nucleon and the Delta(1232) resonance

Abstract

The $\Delta -N$ electromagnetic transition form factors are calculated in the Poincaré covariant quark model in three forms of relativistic kinematics. Addition of $D-$state components to pure $S-$state model wave functions, chosen so as to reproduce the empirical elastic electromagnetic nucleon form factors with single constituent currents, brings the calculated $R_{EM}$ ratio for the $\Delta (1232)\to N\gamma$ transition closer to the empirical values in instant and point form kinematics. The calculated $R_{SM}$ ratio is insensitive to the $D-$state component. In front form kinematics the substantial violation of the angular condition for the spin 3/2 resonance transition amplitude in the impulse approximation prevents a unique determination of $R_{EM}$ and $R_{SM}$, both of which are very sensitive to $D-$state components. In no form of kinematics do $D-$state deformations of the rest frame baryon wave functions alone suffice for a description of the empirical values of these ratios.

arXiv comment11 figures, elsevier format

References in corpus (12)

• Dispersion-Theoretical Analysis of the Nucleon Electromagnetic Formfactors
• Meson-exchange Model for $\pi N$ scattering and $\gamma N->\pi N$ reaction
• Dynamical Study of the Delta Excitation in N(e,e' pi) Reactions
• Electroproduction of the Delta Resonance at High Momentum Transfer
• Electromagnetic Meson Production in the Nucleon Resonance Region
• Baryon Form Factors of Relativistic Constituent-Quark Models
• Shapes of the Proton
• Electromagnetic $N-\Delta$ transition form factors in a light-front constituent quark model
• Deviation of the Nucleon Shape From Spherical Symmetry: Experimental Status
• A light-front description of electromagnetic form factors for $J\le 3/2$ hadrons
• Axial Transition Form Factors and Pion Decay of Baryon Resonances
• Light-front CQM calculations of baryon electromagnetic form factors

Cited by in corpus (9)

• Extraction and Interpretation of gamma N --> Delta Form Factors within a Dynamical Model
• D-state effects in the electromagnetic N-Delta transition
• A Covariant model for the nucleon and the $\Delta$
• Valence quark contribution for the gamma N -> Delta quadrupole transition extracted from lattice QCD
• Electromagnetic Transition Form Factors of Baryon Resonances
• Covariant nucleon wave function with S, D, and P-state components
• Static and dynamic properties of hadronic systems with heavy quarks b and c
• Dynamical coupled-channels: the key to understanding resonances
• Investigation of $\Delta (1232)$ resonance substructure in $p{\gamma }^{\ast }\to \Delta (1232)$ process through helicity amplitudes