Valence-quark structure N* resonances from DSEs
Abstract
We present a unified Quantum Chromodynamics (QCD)-based description of elastic and transition electromagnetic form factors involving the nucleon and its resonances. We compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained using a confining, symmetry-preserving treatment of a vectorvector contact-interaction in a widely-used leading-order (rainbow-ladder) truncation of QCD's Dyson-Schwinger equations. This comparison explains that the contact-interaction framework produces hard form factors, curtails some quark orbital angular momentum correlations within a baryon, and suppresses two-loop diagrams in the elastic and transition electromagnetic currents. Such defects are rectified in our QCD-based approach and, by contrasting the results obtained for the same observables in both theoretical schemes, shows those objects which are most sensitive to the momentum dependence of elementary quantities in QCD.
Cite
@article{arxiv.1801.07251,
title = {Valence-quark structure N* resonances from DSEs},
author = {Jorge Segovia},
journal= {arXiv preprint arXiv:1801.07251},
year = {2018}
}
Comments
Contribution to the proceedings of the 11th International Workshop on the Physics of Excited Nucleons (NSTAR17). Aug. 20-23, 2017. University of South Carolina, Columbia (SC), USA. arXiv admin note: text overlap with arXiv:1602.02768, arXiv:1801.04718, arXiv:1601.00973, arXiv:1611.02844, arXiv:1509.08952