THE N-ASTERISK-]N-ETA BRANCHING RATIOS AND THE QUARK-MODEL

The selectivity of the pi-decay branching ratios of the negative parit y baryon resonances is discussed from a quark model perspective. It is shown that the selectivity can be understood as a consequence of the selective clustering into quark-diquark configurations with different quantum numbers that is caused by the pseudoscalar octet chiral meson exchange interaction between the constituent quarks. This leads to the prediction that the resonances N(1535), Lambda(1670), Sigma(1750) wit h mixed flavour-spin symmetry [21](FS)[21](F)[21](S) in their lowest o rder wavefunctions should have large eta branching ratios, whereas the N(1650) and the Lambda(1800) should not.