Transition Form Factors and Probabilities of the Semileptonic Decays of B and D Mesons within Covariant Light-Front Dynamics.

Electroweak form factors for the decays of heavy B and D mesons are considered within the covariant formulation of light-front dynamics. With the aid of this approach, it is possible to separate the physical and unphysical contributions to the form factors. An analytic expression is obtained for gluon corrections to the electroweak vertex of the vector and the vector-axial quark current, and it is shown that, for constructing a quantitative description of available experimental data, it is important to take into account such corrections to the decay widths of heavy hadrons. The effect of contact interaction on the transition form factors is analyzed, and the importance of taking into account contact interaction for 0-→1-transitions is demonstrated numerically. The elements V[sub bc], V[sub bu], V[sub cs], and V[sub cd] of the Cabibbo-Kobayashi-Maskawa matrix are determined from an analysis of the entire body of data on 0-→ 0- and 0-→ 1-semileptonic decays. Within the experimental errors, the results obtained in this way are intrinsically consistent and comply with world-averaged data. [ABSTRACT FROM AUTHOR]