Exotic Baryons and Monopole Excitations in a Chiral Soliton Model

Abstract

We compute the spectra of exotic pentaquarks and monopole excitations of the low--lying ${1/2}^+$ and ${3/2}^+$ baryons in a chiral soliton model. Once the low--lying baryon properties are fit, the other states are predicted without any more adjustable parameters. This approach naturally leads to a scenario in which the mass spectrum of the next to lowest--lying $J^\pi={1/2}^+$ states is fairly well approximated by the ideal mixing pattern of the $\mathbf{8}\oplus\bar{\mathbf{10}}$ representation of flavor SU(3). We compare our results to predictions obtained in other pictures for pentaquarks and speculate about the spin--parity assignment for $\Xi(1690)$ and $\Xi(1950)$Comment: 16 pages, 2 figures, 6 table