Electromagnetic Properties of Hadrons in a Triplet-Sextet Model

An investigation is made of the electromagnetic mass differences and magnetic moments of the baryons within the framework of a two-particle triplet-sextet model. The mass splittings are assumed to result from $U$-spin-invariant intrinsic mass splittings in the sextet and triplet, and from Coulomb and magnetic spin-spin interactions between the two particles. The two particles are taken to be in an $L=0\mathrm{}$ orbital angular momentum state, and it is assumed that it is valid to use perturbation theory in the calculation of the electromagnetic mass differences. Sum rules and inequalities for the electromagnetic mass differences and magnetic moments are obtained, and the results compared with experiment. A calculation is also made of the electromagnetic mass differences of the $0^{-}$ and $1^{-}$ meson octets. Sum rules and inequalities are again obtained, and the results compared with experiment. All predictions of the triplet-sextet model except one are in agreement with the presently available experimental data. One prediction relating the meson and baryon mass splittings disagrees with the experimental result by 1½ standard deviations. The analogous prediction of the quark model is considerably worse.