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

TL;DR

The HyperCP experiment at Fermilab analyzed a large sample of $ ext{Ω}^-$ hyperon decays to search for rare decay modes, providing new experimental results on these processes.

Contribution

This study presents the first large-scale search for specific rare decay modes of the $ ext{Ω}^-$ hyperon using HyperCP data, including flavor-changing neutral-current decays.

Findings

Measured branching ratios for $ ext{Ω}^- o ext{Ξ}^- ext{π}^+ ext{π}^-$ and $ ext{Ω}^- o ext{Ξ}^0(1530) ext{π}^-$.

Set upper limits on the branching ratio of the rare decay $ ext{Ω}^- o ext{Ξ}^- ext{μ}^+ ext{μ}^-$.

Demonstrated the capability of HyperCP to study rare hyperon decay modes.

Abstract

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.