CHARGE INDEPENDENCE AND SYMMETRY OF NUCLEAR-FORCES

Charge independence and symmetry are approximate symmetries of nature. The observations of the small symmetry breaking effects and the consequences of those effects are reviewed. The effects of the mass difference between up and down quarks and the off shell dependence q(2) of rho(0) - omega mixing are stressed. In particular, I argue that models which predict a strong q(2) dependence of rho(0) - omega mixing seem also to predict a strong q(2) variation for the rho(0) - gamma* matrix element, in contradiction with experiment.