FORM-FACTORS OF SEMILEPTONIC DECAYS OF HEAVY MESONS IN THE QUARK CONFINEMENT MODEL

We compute form factors of the semileptonic decay B(D) --> Xlnu (we denote by X the final pseudoscalar or vector state) within the quark confinement model. As M(Q) --> infinity, one finds that the form factors of the B --> D(D*)enu decay state are expressed in terms of the universal function being dependent on the product of the four-velocities of initial and final heavy mesons in accordance with Isgur-Wise symmetry. At the same time, the form factors of decays with the final light state are found to be monopole functions except the axial-vector form factor A1(t), which goes to a constant in this limit. We compare our results obtained by explicit and asymptotic formulas with other approaches and available experimental data.