Observation of an Excited Ω− Baryon

Abstract

Using data recorded with the Belle detector, we observe a new excited hyperon, an Ω*− candidate decaying into Ξ0K− and Ξ−K0S with a mass of 2012.4±0.7(stat)±0.6(syst) MeV/c2 and a width of Γ=6.4+2.5−2.0(stat)±1.6(syst) MeV. The Ω*− is seen primarily in Υ(1S),Υ(2S), and Υ(3S) decays.