First observation of the decay χcJ → ς+ p KS0 + c. c. (J=0,1,2) FIRST OBSERVATION of the DECAY ... ABLIKIM M. et al

Using E1 radiative transitions ψ(3686)→γχcJ from a sample of (448.1±2.9)×106 ψ(3686) events collected with the BESIII detector, the decays χcJ→ς+pKS0+c.c.(J=0,1,2) are studied. The decay branching fractions are measured to be B(χc0→ς+pKS0+c.c.)=(3.52±0.19±0.21)×10-4, B(χc1→ς+pKS0+c.c.)=(1.53±0.10±0.08)×10-4, and B(χc2→ς+pKS0+c.c.)=(8.25±0.83±0.49)×10-5, where the first and second uncertainties are the statistical and systematic ones, respectively. No evident intermediate resonances are observed in the studied processes.