  Based on an 87-fb$^{-1}$ dataset collected by the Babar detector at the
PEP-II asymmetric-energy $B$-Factory, a search for $D^{0}$--$\bar{D}^{0}$
mixing has been made using the semileptonic decay modes $D^{*+} \to \pi^{+}
D^{0}, D^{0} \to K^{(*)}e\nu$ (+c.c.). The use of these modes allows
unambiguous flavor tagging and a combined fit of the $D^{0}$ decay time and
$D^{*+}$--$D^{0}$ mass difference ($\Delta M$) distributions. The
high-statistics sample of unmixed semileptonic $D^{0}$ decays is used to model
the $\Delta M$ distribution and time-dependence of mixed events directly from
the data. Neural networks are used to select events and reconstruct the
$D^{0}$. A result consistent with no charm mixing has been obtained,
$R_{\rm{mix}}=0.0023 \pm 0.0012 \pm 0.0004$. This corresponds to an upper limit
of $R_{\rm{mix}}<0.0042$ (90% CL).

High Energy Physics - Experiment