Exotic and nonexotic magnetic transitions in the context of the SELEX and GRAAL experiments

Abstract

We calculate magnetic transition moments in the chiral quark-soliton model, with explicit SU(3)-symmetry breaking taken into account. The dynamical model parameters are fixed by experimental data for the magnetic moments of the baryon octet and from the recent measurements of $\hat{I}{˜}^{+}$ mass. Known magnetic transition moments $\hat{I}{¼}_{\hat{I}›\hat{I}\pounds }$, $\hat{I}{¼}_{N\hat{I}”}$ are reproduced and predictions for other octet-decuplet and octet-antidecuplet transitions are given. In particular $\hat{I}{¼}_{\hat{I}\pounds \hat{I}{\pounds }^{\ast }}$ recently constrained by SELEX is shown to be below $0.82\hat{I}{¼}_N$. The recent GRAAL data on $\hat{I}\cdot$ photoproduction off the nucleon are explained in terms of a new narrow antidecuplet neutron-like resonance.

14 pages, 9 figures. Final version accepted for publication in Phys.Rev.D