$\Omega^-$ Hyperon Decay Modes with the HyperCP Experiment at Fermilab

The HyperCP experiment (Fermilab E871) has the largest recorded sample of $\Omega^-$ hyperon decays, allowing new searches for three rare decay modes, each with five charged tracks in the final state. Results are presented for $\Omega^-\to\Xi^-\pi^+\pi^-$; $\Omega^- \to \Xi^0(1530)\pi^-$; and the flavor-changing neutral-current decay $\Omega^- \to \Xi^-\mu^+\mu^-$. Normalization of these measurements were to the decay $\Omega^- \to \Lambda K^-$ with a five-track topology similar to the signal mode with the subsequent decay of $\Lambda \to p \pi^-$ and $K^- \to \pi^- \pi^+ \pi^-$ in the decay volume.