This paper considers the implications of the heavy quark and chiral symmetries for the semileptonic decay $B\to D^{*}\mathrm{Xl}{\overline{\nu }}_l$. The general kinematic analysis for decays of the form pseudoscalar meson→vector meson+pseudoscalar meson+lepton+antilepton is presented. This formalism is applied to the above exclusive decay which allows the differential decay rate to be expressed in a form that is ideally suited for the experimental determination of the different form factors for the process through angular distribution measurements. Heavy quark and chiral symmetry predictions for the form factors are presented, and the differential decay rate is calculated in the kinematic region where chiral perturbation theory is valid.

• Received 30 November 1992

DOI:https://doi.org/10.1103/PhysRevD.48.2121