Model-Independent Determination of the Spin of the Ω- and Its Polarization Alignment in Ψ(3686) → Ω-Ω‾+

• We present an analysis of the process ψ(3686)→Ω−¯Ω+ (Ω−→K−Λ, ¯Ω+→K+¯Λ, Λ→pπ−, ¯Λ→¯pπ+) based on a dataset of 448×106  ψ(3686) decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process ψ(3686)→Ω−¯Ω+ and the decay parameters of the subsequent decay Ω−→K−Λ (¯Ω+→K+¯Λ) are measured for the first time by a fit to the angular distribution of the complete decay chain, and the spin of the Ω− is determined to be 3/2 for the first time since its discovery more than 50 years ago.

Subject headings

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)