Chiral soliton models, large N_c consistency and the Theta^+ exotic baryon

Predictions for a light collective ${\mathrm{\Theta }}^{+}$ baryon state (with strangeness +1) based on the collective quantization of chiral soliton models are shown to be inconsistent with large $N_c$ QCD. The lightest strangeness +1 state to emerge from the analysis has an excitation energy which at large $N_c$ scales as $N_c^0$ while collective quantization is legitimate only for excitations which go to zero as $N_c\to \mathrm{\infty }$. This inconsistency strongly suggests that predictions for ${\mathrm{\Theta }}^{+}$ properties based on collective quantization of chiral solitons are not valid.