Study of $B^- \to \omega \ell^- \bar\nu_\ell$ decays at {\sc BaBar}

We present an analysis of $B^- \to \omega \ell^- \bar\nu_\ell$ decays based on a sample of 470 million $B\overline{B}$ pairs recorded with the {\sc BaBar} detector at the $\Upsilon(4S)$ resonance. We use a data sample from the sidebands of the $m_{3\pi}$ distribution to model the combinatoric $\omega$-candidates background, which is the largest source of background. We measure the branching fraction for this decay in three bins of $q^2$, the squared momentum transfer, and compare the distribution with predictions based on theoretical form-factor calculations.