2-COMPONENT SEMILEPTONIC FORM-FACTORS

In the semileptonic decays of a heavy quark to a light quark, present models disagree in an essential fashion concerning the shape of the form factors. Both the heavy quark limit of QCD and dispersion relations suggest that the correct form factors contain two distinct contributions. We discuss these as applied to the B --> pi-ev and B --> rho-ev decays. We also describe the inconsistencies of available phenomenological models and discuss how they must be modified.