2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44990I review the QCD sum rules calculations of the form factors governing the semileptonic decays of charmed and beauty mesons. In particular, I discuss the predicted dependence of the various form factors on $q^2$ and how it can be obtained for the form factors of vector and axial currents. In some cases the $q^2$ dependence, computed by QCD sum rules, is different from the outcome of lattice QCD. A Tau-Charm factory could be an efficient tool to study this aspect of the charmed meson transitions.Latex, 12 pages, 2 figures (PostScript files included), BARI-TH/93-152. Talk delivered at the 3rd Workshop on a Tau-Charm Factory, Marbella (Spain) 1-6 June 1993High Energy Physics - Phenomenologytext