Sudakov suppression in the soft heavy to light meson transition form   factor
  We calculate hard gluon contribution to the decay vertex that determines the heavy-to-light meson transition form factor at large recoil. It is found that resulting Sudakov suppression significantly decreases the soft, wave function dependent contribution to the form factor. Phenomenological implications of these findings are discussed. 
Adam P. Szczepaniak and Anatoly Radyushkin