Coupling constants of the $S_{11}$ resonances to pseudoscalar mesons and octet baryons

Abstract

Coupling constants of $S_{11}(1535)$ and $S_{11}(1650)$ resonances to meson-baryon ($\pi N$, $\eta N$, $\eta^\prime N$, $KY$) are investigated in a chiral quark model, complemented by inclusion of five-quark components in those resonances. The known strong decay partial widths of both resonances are well reproduced, provided sizeable strangeness components in the relevant wave functions. %to excellent description for the strong decays of the above two resonances, which %cannot be reproduced very well in the traditional chiral quark model with or without %$SU(6)\otimes O(3)$ breaking. Finally, we find that $S_{11}(1535)$ and $S_{11}(1650)$ %couple strongly to the channels with strangeness.