Heavy-to-light form factors in the quark model with heavy propagators

We calculate the heavy-to-light form factors in the relativistic quark model with heavy infrapropagators. Their q^2-dependence in the physical region is defined by two parameters: the "infrared" parameter \nu characterizing the infrared behavior of the heavy quark and the mass difference of the heavy meson and heavy quark E=m_H-M_Q. It is found that the values of the D\to K(K^*) and D\to \pi(\rho) form factors at q^2=0 are in excellent agreement with the available experimental data and other approaches whereas these values for B\to \pi(\rho) transitions are found to be larger than those of several other models. The obtained form factors are used to calculate the widths of the semileptonic decays of B and D mesons. The comparison of our results with the available experimental data and other approaches is givenComment: 15 pages, 3 eps figures. New references are added, corrected some typos. To appear in Few-Body System