First Evidence of Lambda Lambda-bar in χ_cJ Decays

Abstract

The first observation of χ_cJ (J=0,1,2) decays to Lambda Lambda-bar is reported using ψ(2S) data collected with the BESII detector at the BEPC. The branching ratios are determined to be BR(χ_c0 \to Lambda Lambda-bar) = (4.7^{+1.3}_{-1.2} \pm 1.0)\times 10^{-4}, BR(χ_c1 \to Lambda Lambda-bar) = (2.6^{+1.0}_{-0.9} \pm 0.6)\times 10^{-4} and BR(χ_c2 \to Lambda Lambda-bar) = (3.3^{+1.5}_{-1.3} \pm 0.7)\times 10^{-4}. Results are compared with model predictions.