COVARIANT AND HEAVY-QUARK SYMMETRICAL QUARK MODELS

There exist relativistic quark models (potential or MIT bag) which sat isfy the heavy quark symmetry (HQS) relations among meson decay consta nts and form factors. A covariant construction of the momentum eigenst ates, developed here, can correct for spurious center-of-mass motion c ontributions. The proton form factor and M1 transitions in quarkonia a re calculated. An explicit expression for the Isgur-Wise function is f ound and model-determined deviations from HQS a;re studied. All result s depend on the model parameters only. No additional ad hoc assumption s are needed.