HEAVY-QUARK SYMMETRIES IN FORM-FACTORS AT LARGE RECOIL

It has recently been shown that hadrons containing a single heavy quark exhibit a new flavor-spin symmetry of QCD, and that this symmetry leads to relations between operator matrix elements involving such hadrons. On examining mechanisms that might break the symmetry at large recoil, I conclude that these relations are probably valid over the full kinematic ranges available in transitions involving b --> c, b --> s, b --> u, c --> s, and c --> d currents.