SEMILEPTONIC B-]D(ASTERISK)LV DECAYS, THE SLOPE OF ISGUR-WISE FUNCTION AND VERTICAL-BAR-V-BC-VERTICAL-BAR VALUE IN POTENTIAL QUARK-MODEL

The modification of the naive potential model of the heavy meson is considered on the basis of the single-time prescription for the quark-meson form factor and the covariant choice of the quark relative momentum. The application of the model to the description of the semileptonic decays of the beauty meson allows one to determine the Isgur Wise function slope rho(2) similar or equal to 0.94 and to extract the value \V-bc\ = 0.036 +/- 0.002 from the experimental data.