Observation of ψ (3686)→ Ξ (1530)- Ξ ̄ (1530)+ and Ξ (1530)- Ξ ̄ + OBSERVATION of ... ABLIKIM M. et al.

Abstract

Using 448.1×106 ψ(3686) events collected with the BESIII detector at BEPCII, we employ a single-baryon tagging technique to make the first observation of ψ(3686)→Ξ(1530)-Ξ̄(1530)+ and Ξ(1530)-Ξ̄+ decays with a statistical significance of more than 10σ and 5.0σ, respectively. The branching fractions are measured to be B(ψ(3686)→Ξ(1530)-Ξ̄(1530)+)=(11.45±0.40±0.59)×10-5 and B(ψ(3686)→Ξ(1530)-Ξ̄+)=(0.70±0.11±0.04)×10-5. The angular distribution parameter for ψ(3686)→Ξ(1530)-Ξ̄(1530)+ is determined to be α=0.40±0.24±0.06, which agrees with the theoretical predictions within 1σ. The first uncertainties are statistical, and the second systematic.