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 $q^2$, are predicted in several models. We present preliminary results for the parameters r$_{2}$ and r$_{V}$ based on roughly 300 fb$^{-1}$ of BaBar data. The high statistics allow us to make a significant improvement over the precision of previous results.