Measurements of ? (3686) ?k- ? ? ¯ ++ c. c. and ? (3686) ??K- ? ? ¯ ++ c. c.

Abstract

Using a sample of 1.06×108?(3686) events produced in e+e- collisions at s=3.686 GeV and collected with the BESIII detector at the BEPCII collider, we present studies of the decays ?(3686)?K-??¯++c.c. and ?(3686)??K-??¯++c.c.. We observe two hyperons, ?(1690)- and ?(1820)-, in the K-? invariant mass distribution in the decay ?(3686)?K-??¯++c.c. with significances of 4.9? and 6.2?, respectively. The branching fractions of ?(3686)?K-??¯++c.c., ?(3686)?K-?0?¯++c.c., ?(3686)???cJ??K-??¯++c.c. (J=0, 1, 2), and ?(3686)??(1690/1820)-?¯++c.c. with subsequent decay ?(1690/1820)-?K-? are measured for the first time. © 2015 American Physical Society.