Study of the J/ψ decays to ΛΛ¯ and Σ0Σ¯0

Using 58 million J/ψ events collected by the BES-II detector at the BEPC, the decays J/ψ→ΛΛ¯ and Σ0Σ¯0 are analysed. The branching fractions are measured to be Br(J/ψ→ΛΛ¯)=(2.03±0.03±0.15)×10−3 and Br(J/ψ→Σ0Σ¯0)=(1.33±0.04±0.11)×10−3. The angular distribution is of the form dNdcosθ=N0(1+αcos2θ), with α=0.65±0.11±0.03 for J/ψ→ΛΛ¯ and α=−0.24±0.19±0.07 for J/ψ→Σ0Σ¯0.