We have measured the α parameter of the Ω- → ΔK- decay using data collected with the HyperCP spectrometer during the 1997 fixed-target run at Fermilab. Analyzing a sample of 0.96 × 106 Ω- → ΛK-, Λ → pπ- decays, we obtain αΩα Λ = [1.33 ± 0.33(stat) ± 0.52(syst) × 10-2. With the accepted value of αΛ, αΩ is found to be [2.07 ± 0.51(stat) ± 0.81(syst)] × 10-2. © 2005 The American Physical Society.
