Strong and Radiative $D^\ast$ Decays
  We use the relativistic light--front quark model to show that both strong and radiative $D^\ast$ decays are in good agreement with the 1992 CLEO II results. In particular the coupling for $D^{\ast}\ra D \pi$ is consistent with the experimental upper limit. The key point is the relativistic treatment of the quark spin. 
Patrick J. O'Donnell and Q. P. Xu