Absolute $D$ hadronic branching fractions

Using 281 pb$^{-1}$ of $e^+e^-$ collisions recorded at the $\psi(3770)$ resonance with the CLEO-c detector at CESR, we determine absolute hadronic branching fractions of charged and neutral $D$ mesons using a double tag technique. Among measurements for three $D^0$ and six $D^+$ modes, we measure reference branching fractions ${\cal B}(D^0 \to K^- \pi^+)$ and ${\cal B}(D^+ \to K^- \pi^+ \pi^+)$. Using a determination of the integrated luminosity, we also extract the cross sections $\sigma(e^+e^- \to D^0 \bar{D}^0)$ and $\sigma(e^+e^- \to D^+D^-)$.