United Nations Educational Scientific and Cultural Organization INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS 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)× U(3) symmetry, are applied to the calculation of current s – quark mass corrections to the form factors of the D → K̄ e νe and D → K̄ 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. MIRAMARE – TRIESTE November 1994 Permanent Address: Department of Theoretical Physics, State Technical University, 195251 St. Petersburg, Russian Federation.