Observation of the decay $\ensuremath{\psi}\mathbf{(}3686\mathbf{)}\ensuremath{\rightarrow}\ensuremath{\Lambda}{\overline{\ensuremath{\Sigma}}}^{\mathbf{\ifmmode\pm\else\textpm\fi{}}}{\ensuremath{\pi}}^{\mathbf{\ensuremath{\mp}}}\mathbf{+}\mathbf{c}.\mathbf{c}.$

Observation of the decay $ψ (3686) \to Λ {\bar{Σ}}^{\pm} π^{\mp} + c . c .$

M. Ablikim et al. (BESIII Collaboration)

Phys. Rev. D 88, 112007 – Published 13 December 2013

Abstract

Using a sample of $1.06 \times 10^{8}$ $ψ (3686)$ events collected with the BESIII detector, we present the first observation of the decays of $ψ (3686) \to Λ {\bar{Σ}}^{+} π^{-} + c . c .$ and $ψ (3686) \to Λ {\bar{Σ}}^{-} π^{+} + c . c .$ The branching fractions are measured to be $B (ψ (3686) \to Λ {\bar{Σ}}^{+} π^{-} + c . c .) = (1.40 \pm 0.03 \pm 0.13) \times 10^{- 4}$ and $B (ψ (3686) \to Λ {\bar{Σ}}^{-} π^{+} + c . c .) = (1.54 \pm 0.04 \pm 0.13) \times 10^{- 4}$ , where the first errors are statistical and the second ones systematic.