Heavy-to-Light Form Factors in the Quark Model with Infrared Heavy-Quark Propagators

We calculate the heavy-to-light form factors in a relativistic quark model with infrared heavy-quark propagators. Their -dependence in the physical region is defined by two parameters: the “infrared” parameter characterizing the infrared behaviour of the heavy quark and the mass difference of the heavy meson and the heavy quark . It is found that the values of the and form factors at are in excellent agreement with the available experimental data and other approaches whereas for transitions these values 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 and mesons. A comparison of our results with available experimental data and other approaches is presented. Received January 31, 1997; revised July 15, 1997; accepted for publication January 20, 1998