Measurements of $\ddot{I}ˆ(3686)\to K^{-}\hat{I}›\bar{\hat{I}}{ž}^{+}+c.c.$ and $\ddot{I}ˆ(3686)\to {\hat{I}}^3{K}^{-}\hat{I}›\bar{\hat{I}}{ž}^{+}+c.c$

Abstract

Using a sample of $1.06\times10^8\ \psip$ events produced in $e^{+}{e}^{-}$ collisions at $\sqrt{s}$ = 3.686 GeV and collected with the BESIII detector at the BEPCII collider, we present studies of the decays $\klx+c.c.$ and $\gklx+c.c.$. We observe two hyperons, $\hat{I}ž(1690{)}^{-}$ and $\hat{I}ž(1820{)}^{-}$, in the $K^{-}\hat{I}›$ invariant mass distribution in the decay $\klx+c.c.$ with significances of $4.9\ddot{I}ƒ$ and $6.2\ddot{I}ƒ$, respectively. The branching fractions of $\klx+c.c.$, $\ksx+c.c.$, $\psip\toγχ_{cJ}\to γK^- Λ\barΞ^+ +c.c.$ $(J=0,1,2)$, and $\psip\to Ξ(1690/1820)^{-} \barΞ^++c.c$ with subsequent decay $\hat{I}ž(1690/1820{)}^{-}\to K^{-}\hat{I}›$ are measured for the first time.

11 pages, 6 figures