Observation of the decay ψ(3686) → Λ∑¯± π∓ + c.c.

Abstract

Using a sample of 1.06 × 108 ψ(3686) events collected with the BESIII detector, we present the first observation of the decays of ψ(3686) → Λ∑¯+ π- + c.c. and ψ(3686) → Λ∑¯- π+ + c.c. The branching fractions are measured to be B(ψ(3686) → Λ∑¯- π+ + c.c.) = (1.40 ± 0.03 ± 0.13) × 10-4 and B(ψ(3686) → Λ∑¯- π+ + c.c.) = (1.54 ± 0.04 ± 0.13) × 10-4, where the first errors are statistical and the second ones systematic. © 2013 American Physical Society.