Measurement of Ω- decay properties in the CERN SPS hyperon beam

In an experiment in the CERN SPS charged hyperon beam, a sample of 16,000 Ω- decays was collected at an Ω- momentum of 131 GeV/c. The Ω- lifetime, the branching ratios and decay asymmetry parameters for the main decay modes were measured, giving: tausub(Ω-) =(0.823 +- 0.015) x 10-10s. For the rare decay modes the branching ratios were obtained. A sample of 32,000 Ψ- decays collected under the same experimental conditions gave a new measurement of the Ψ- lifetime: tausub(Ψ-) = (1.652 +- 0.051) X 10-10s. Combining the measurements of the present experiment with those obtained in a previous experiment in the SPS hyperon beam gives: tausub(Ω-) = (0.823 +- 0.013) X 10-10s. The experimental results are compared with theoretical calculations