ELECTROMAGNETIC-MASS DIFFERENCES OF THE OCTET AND DECUPLET BARYONS

The general parametrization method [Phys. Rev. D 40, 2997 (1989)], an exact consequence of any QCD-like relativistic field theory, is used to parametrize the electromagnetic mass differences of the baryons. First we show that the Coleman-Glashow relationship, derived neglecting flavor breaking, continues to hold if all flavor-breaking terms are kept, except the three-quark ones; this may explain why the formula agrees so well with the data. In addition, neglecting only three-quark terms, we reproduce some equalities between electromagnetic mass differences of 8 and 10 baryons derived a long time ago [A. Gal and F. Scheck, Nucl. Phys. B2, 110 (1967)] by the nonrelativistic quark model (NRQM). Also these equalities, now testable due to the improved knowledge of decuplet masses, are well satisfied; they now appear as a general consequence of a relativistic QCD-like field theory, not just of the NRQM.