Measurement of the Spin of the Ω− Hyperon

Abstract

A measurement of the spin of the Ω − hyperon produced through the exclusive process Ξ 0 c → 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 Ξ 0 c has spin 1 / 2 , the angular distribution of the Λ from Ω − → Λ K − decay is inconsistent with all half-integer Ω − spin values other than 3 / 2 . Lower statistics data for the process Ω 0 c → Ω − π + from a 230 fb − 1 sample are also found to be consistent with Ω − spin 3 / 2 . If the Ξ 0 c spin were 3 / 2 , an Ω − spin of 5 / 2 could not be excluded.