D0 Hot Topics
  We present recent DO results based on approximately 1 fb$^{-1}$ of $p \bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV recorded at the Fermilab Tevatron. Preliminary results on a search for the flavor changing neutral current process $D^+\to \pi^+\mu^+\mu^-$, a measurement of the CP violation parameter in $B$ mixing, $\epsilon_B$, and a two sided limit on the $B_s$ oscillation frequency $\Delta m_s$ are presented. The limits on $\epsilon_B$ and ${\cal B}(D^+\to \pi^+\mu^+\mu^-)$ are the world's best limits. The two sided bound on $\Delta m_s$ is the first direct indication by a single experiment that $\Delta m_s$ is bounded from above. 
D. Buchholz (for the D0 Collaboration)