  Roles of quark-pair correlations in the baryon structure and the hyperon
non-leptonic weak decay are studied within the non-relativistic constituent
quark model. We construct the SU(3) ground state baryons by solving the three
body problem rigorously with the confinement force and the short range
spin-dependent attraction. We emphasize the importance of the $s=0$ quark-quark
correlation to reproduce the $\Delta I=1/2$ enhancement of the hyperon decay,
and demonstrate that resulting static properties as well as the decay
amplitudes agree with the experiments, if we deal with the $s=0$ correlation
properly. Special attention is also put on the consequences of the SU(6)
spin-flavor symmetry breaking due to the $s=0$ correlation. Calculated magnetic
moments are the almost same as the naive SU(6) predictions in spite of the
existence of the strong correlations.
