Composite Models andSU(6)Invariance

In this paper we discuss a nonrelativistic model for the baryons and the baryon resonances based on three quarks with fractional charges. It is shown that it is possible to have the ground state to correspond to the 56-dimensional representation of $\mathrm{SU}\left(6\right)\mathrm{}$ by introducing attractive three-body forces on which are superimposed weaker repulsive two-body forces. The departure from the $\mathrm{SU}\left(6\right)\mathrm{}$-symmetrical limit is discussed in terms of three types of exchange forces which turn out to be of the same order of magnitude.