Towards a BF and Form Factor Measurement in $D^0\to K^{\ast -}e^+\nu _e $ Decays

Using data from the BaBar experiment, we study form factors in $D^0\to K^{\ast -}e^+\nu _e $ decays. These form factors, which are Lorentz-invariant functions of $q^2$ and decay angles, are predicted in several models. We expect to obtain high statistics in this decay mode and therefore to measure the form factors in a model-independent way. At this point we present very preliminary results based on a small subsample of available data.