Electromagnetic form factors of the Delta(1232) in Dual-Large N_c QCD

TL;DR

This paper models the electromagnetic form factors of the Delta(1232) resonance using a Dual Resonance Model in large N_c QCD, fitting data and predicting related form factors with good experimental agreement.

Contribution

It introduces a Dual Resonance Model approach to calculate Delta(1232) form factors in large N_c QCD, fitting data with a single free parameter and predicting chiral EFT form factors.

Findings

Good agreement with experimental data for all three form factors.

Single free parameter fixed by data fitting.

Predicted q^2-dependence of chiral EFT form factors.

Abstract

The three electromagnetic form factors of the $\Delta(1232)$ resonance, $G^*_M(q^2)$, $G^*_E(q^2)$, and $G^*_C(q^2)$ are obtained in the space-like region using a Dual Resonance Model realization of QCD in the large $N_c$ limit (Dual-${QCD}_{\infty}$). Each form factor involves a single free parameter which is fixed by fitting data on $G^*_M(q^2)$, and on the ratios $R_{EM}(q^2)$ and $R_{SM}(q^2)$. Good agreement with experiment is obtained for all three quantities. Results are then used to predict the $q^2$-dependence of the chiral effective-field theory form factors $g_M(q^2)$, $g_E(q^2)$, and $g_C(q^2)$.