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 infinity, and Chiral perturbation theory at the quark level, based on the extended Nambu - Jona - Lasinio model with linear realization of chiral U(3) x U(3) symmetry, are applied to the calculations of current s - quark mass corrections to the form factors of the D → K-bar e+ νe and D → K-bar* e+ νe decays. These corrections turn out to be quite significant, of the order of 7 - 20%. The theoretical results are compared with experimental data. (author). 17 refs