Model-Independent Determination of the Spin of the Ω- and Its Polarization Alignment in ψ(3686) → Ω-(Ω)over-bar+

作者：Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Amoroso, A.; An, Q.; Anita; Bai, Y.; Bakina, O.; Ferroli, R. Baldini; Balossino, I; Ban, Y.; Begzsuren, K.; Bennett, J., V; Berger, N.; Bertani, M.; Bettoni, D.; Bianchi, F.; Biernat, J.; Bloms, J.; Bortone, A.; Boyko, I; Briere, R. A.; Cai, H.; Cai, X.; Calcaterra, A.; Cao, G. F.; Cao, N.; Cetin, S. A.; Chang, J. F.; Chang, W. L.; Chelkov, G.; Chen, D. Y.; Chen, G.; Chen, H. S.; Chen, M. L.; Chen, S. J.; Chen, X. R.

来源：Physical Review Letters, 2021, 126(9): 092002.

DOI：10.1103/PhysRevLett.126.092002

• VIOLATION
• BARYONS
• DECAYS

We present an analysis of the process psi(3686) -> Omega(-)(Omega) over bar (+)(Omega(-). K-Lambda, (Omega) over bar (+) K+ (Lambda) over bar,(Omega) over bar (+) Lambda -> p pi(-), (Lambda) over bar -> p (p) over bar pthorn) based on a dataset of 448 x 10(6) psi(o3686) decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process psi(368)-> O-O<overline> thorn and the decay parameters of the subsequent decay O-. K-. oO<overline> thorn. Kthorn.<overline> THORN are measured for the first time by a fit to the angular distribution of the complete decay chain, and the spin of the O- is determined to be 3=2 for the first time since its discovery more than 50 years ago.