Abstract :
The constituent picture of hadrons implies certain quantum mechanical inequalities which must hold in the potential models. Based on this qualitative consideration I argue that it is not easy to significantly increase the scale of the flavour-dependent 1mb3 effects within the heavy quark expansion while preserving the conventional constituent picture of heavy flavour hadrons. I briefly address the physical consequences that might be expected if an attempt to push the effects of weak scattering and interference above the 10% level within 1mb expansion is made without invoking qualitatively different mechanisms, including violations of duality.
