Weak decays of heavy mesons in a covariant quark model

Abstract

In this paper we investigate weak decays of heavy mesons in the framework of a covariant quark model, which is based on the Bethe-Salpeter equation in instantaneous approximation. Apart from a phenomenological confinement potential, a residual interaction induced by instantons is adopted. Masses and many decay observables of light mesons have already been described successfully in this model (Eur. Phys. J. A 9, 73 (2000); 221). An appropriate extension allows a unified description of light and heavy systems. Using a set of parameters, which are fixed by the mass spectra, we evaluate the form factors of semileptonic decays of charmed and bottom mesons. In the heavy-quark limit these can be reduced to the Isgur-Wise function, which is calculated. Finally, the form factors are used to determine the non-leptonic decay rates of B-mesons in the factorization approximation.