The $$\varLambda (1405)$$ resonance as a genuine three-quark or molecular state

The mechanism for the formation of $\Lambda(1405)$ resonance is studied in a chiral quark model that includes quark-meson as well contact (four point) interactions. negative-parity $S$-wave scattering amplitudes strangeness $-1$ and $1$ are calculated within unified coupled-channel framework $KN$, $\bar{K}N$, $\pi\Sigma$, $\eta\Lambda$, $K\Xi$, $\pi\Lambda$, $\eta\Sigma$ channels possible genuine three-quark bare singlet octet states corresponding to $\frac12^-$ resonances. We show order reproduce $S_{01}$ partial wave it important include pertinent state, while inclusion term not mandatory. Laurent-Pietarinen expansion used determine $S$-matrix poles. Following their evolution function increasing interaction strength, mass state strongly reduced due attractive self-energy $\pi\Sigma$ $\bar{K}N$ channels; when drops below $KN$ threshold, acquires dominant component which can be identified with molecular state. attraction between kaon nucleon generated through $\bar{K}N\Lambda^*$ rather than by meson-nucleon forces.