First observation of χcJ→ωω decays

Decays of χc0,2→ωω are observed for the first time using a sample of 14.0×106ψ(2S) events collected with the BESII detector. The branching ratios are determined to be B(χc0→ωω)=(2.29±0.58±0.41)×10−3 and B(χc2→ωω)=(1.77±0.47±0.36)×10−3, where the first errors are statistical and the second systematic. The significances of the two signals are 4.4σ and 4.7σ, respectively.