Measurement of the Spin of the Ω− Hyperon

A measurement of the spin of the Ω− hyperon produced through the exclusive process Ξ0c→Ω−K+ is presented using a total integrated luminosity of 116  fb−1 recorded with the BABAR detector at the e+e− asymmetric-energy B factory at SLAC. Under the assumption that the Ξ0c has spin 1/2, the angular distribution of the Λ from Ω−→ΛK− decay is inconsistent with all half-integer Ω− spin values other than 3/2. Lower statistics data for the process Ω0c→Ω−π+ from a 230  fb−1 sample are also found to be consistent with Ω− spin 3/2. If the Ξ0c spin were 3/2, an Ω− spin of 5/2 could not be excluded.