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

B. Julia-Diaz·D. O. Riska
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Abstract

The $Δ-N$ 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 $Δ(1232)\to Nγ$ 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.

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B. Julia-Diaz, D. O. Riska. 2004-11-02. D-state configurations in the electromagnetic form factors of the nucleon and the Delta(1232) resonance. https://doi.org/10.1016/j.nuclphysa.2005.04.008

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