Dirac form factors and electric charge radii of baryons in the combined chiral and 1/N_c expansions

TL;DR

This paper calculates baryon Dirac form factors and charge radii using combined chiral and 1/N_c expansions, incorporating loop effects and decuplet-octet mass differences, and finds good agreement with experimental data.

Contribution

It introduces a systematic one-loop large-N_c baryon chiral perturbation theory approach including decuplet states and mass differences, improving theoretical predictions.

Findings

Predictions agree well with experimental data.

Large-N_c cancellations simplify the analysis.

Charge radii are computed with detailed numerical analysis.

Abstract

The baryon Dirac form factor is computed at one-loop order in large-N_c baryon chiral perturbation theory, where N_c is the number of color charges. Loop graphs with octet and decuplet intermediate states are systematically incorporated into the analysis and the effects of the decuplet-octet mass difference are accounted for. There are large-N_c cancellations between different one-loop graphs as a consequence of the large-N_c spin-flavor symmetry of QCD baryons. As a byproduct, the mean-square charge radius is also computed through a detailed numerical analysis. The predictions of large-N_c baryon chiral perturbation theory are in very good agreement both with the expectations from the 1/N_c expansion and with the experimental data.