Electromagnetic form factors of the Δ(1232) in dual-large N<sub>c</sub> QCD
Cesareo A. Dominguez; Raoul Röntsch; Cesareo A. Dominguez; Institute of Theoretical Physics and Astrophysics, University of Cape Town, Rondebosch 7700, South Africa; Raoul Röntsch; Institute of Theoretical Physics and Astrophysics, University of Cape Town, Rondebosch 7700, South Africa
Журнал:
Journal of High Energy Physics
Дата:
2007-10-01
Аннотация:
The three electromagnetic form factors of the Δ(1232) resonance, G*<sub>M</sub>(q<sup>2</sup>), G*<sub>E</sub>(q<sup>2</sup>), and G*<sub>C</sub>(q<sup>2</sup>) are obtained in the space-like region using a Dual Resonance Model realization of QCD in the large N<sub>c</sub> limit (Dual-QCD<sub>∞</sub>). Each form factor involves a single free parameter which is fixed by fitting data on G*<sub>M</sub>(q<sup>2</sup>), and on the ratios R<sub>EM</sub>(q<sup>2</sup>) and R<sub>SM</sub>(q<sup>2</sup>). Good agreement with experiment is obtained for all three quantities. Results are then used to predict the q<sup>2</sup>-dependence of the chiral effective-field theory form factors g<sub>M</sub>(q<sup>2</sup>), g<sub>E</sub>(q<sup>2</sup>), and g<sub>C</sub>(q<sup>2</sup>).
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