Measuring the absolute {\boldmath $D^{0} \to K_{s} \pi^{0}$} branching fraction

We describe an algorithm for measuring the absolute branching fraction of the $D^{0}\to K_{s}\pi^{0}$ decay using Monte Carlo data from the BaBar experiment at SLAC. The power of this algorithm comes from identifying and counting the number of slow pions, $\pi_{s}$, from charged $D^{*}$ decay in $c\overline{c}$ events in which the flavor of the $D^{*}$ is consistent with the flavor of a fully reconstructed second charm decay, referred to as the tag, in the same event. The analysis uses three tagging samples: $D^{+}\to K^{*}\pi^{+}\pi^{+}$, $D^{*}\to D^{0}\pi^{+}$ with $D^{0}\to K^{-}\pi^{+}\pi^{0}$ and $D^{0}\to K^{-}\pi^{+}$ with an additional tag created by requiring the $D^{0}$ to come from a $D^{*+}$ along with a $\pi^{+}$. With 400 fb${}^{-1}$ of data, the branching fraction can be measured with 5\% precision, accounting for both the statistical and systematic uncertainties.