QUARK-MODEL EXPLANATION OF THE N-ASTERISK-]N-ETA BRANCHING RATIOS

The constituent quark model can explain the strong selectivity of the N eta decay branching ratios of the nucleon resonances if the fine str ucture interaction between the constituent quarks is described in term s of Goldstone boson exchange. This chiral quark model predicts that t he resonances N(1535), N(1710), Lambda(1670), Sigma(1750), which have mixed flavor and spin symmetry [21](FS)[21](F)[21](s) wavefunctions in lowest order, should have large N eta branching ratios, while N eta d ecay of the other resonances that have different flavor-spin symmetry should be strongly suppressed in agreement with the experimental branc hing ratios.