CURRENT S-QUARK MASS CORRECTIONS TO THE FORM-FACTORS OF D-MESON SEMILEPTONIC DECAYS

The infinite mass effective theory, when a heavy quark mass tends to i nfinity, and Chiral perturbation theory at the quark level, based on t he extended Nambu-Jona-Lasinio model with linear realization of chiral U(3) x U(3) symmetry, are applied to the calculation of current s-qua rk mass corrections to the form factors of the D --> ($) over bar K e( +) v(e) and D --> ($) over bar K e(+)v(e) decays. These corrections t urn out to be quite significant, of the order of 7-20%. The theoretica l results are compared with experimental data.