Baryon Octet Electromagnetic Form Factors in a confining NJL model

Abstract

Electromagnetic form factors of the baryon octet are studied using a Nambu--Jona-Lasinio model which utilizes the proper-time regularization scheme to simulate aspects of colour confinement. In addition, the model also incorporates corrections to the dressed quarks from vector meson correlations in the t-channel and the pion cloud. Comparison with recent chiral extrapolations of lattice QCD results shows a remarkable level of consistency. For the charge radii we find the surprising result $r_{E}^p < r_{E}^{\Sigma^+}$ and $|r_{E}^n| < |r_{E}^{\Xi^0}|$, whereas the magnetic radii have a pattern largely consistent with a naive expectation based on the dressed quark masses.