Sympletic symmetry as an alternative approach to charm and color

The detection of weak neutral currents and the discovery of the heavy vector meson psi suggest the necessity of extending the SU(3) symmetry. The usual extensions of SU(3) (charm or colour) invoke extra conserved quantum numbers and consequently increase the dimensions of the fundamental representation (number of quarks). It is shown that the observed extra degrees of freedom may be taken into consideration by just increasing the number of quarks without invoking new conserved quantities. (Z.J.)