Structure of ${\lambda }^{\ast }$(1405) and the ${\lambda }^{\ast }$-Meson-Baryon Coupling Constants

Within an extended chiral constituent quark model, three- and five-quark structure of the $S_{01}$ resonance $\mathrm{\Lambda }(1405)$ is investigated with respect to the coupling constants $g_{{\mathrm{\Lambda }}^{\ast }\pi \mathrm{\Sigma }}^2$ and $g_{{\mathrm{\Lambda }}^{\ast }\bar{K}N}^2$. Our findings corroborate with about 50% of five-quark admixture in the $\mathrm{\Lambda }(1405)$ needed in reproducing the strong decay width, ${\mathrm{\Gamma }}_{\mathrm{\Lambda }(1405)\to (\mathrm{\Sigma }\pi {)}^{\circ }}$.