Search for the non-D\barD Decay psi(3770) --> K_S^0 K_L^0
  Using the current world's largest data sample of psi(3770) decays, we present results of a search for the non-DDbar decay psi(3770) -> KsKl. We find no signal, and obtain an upper limit of Sigma(psi(3770) -> KsKl) < 0.07 pb at 90% confidence level (CL). Our result tests a theoretical prediction for the upper bound on B(psi(3770) -> KsKl) based on a charmonia-mixing model. 
D. Cronin-Hennessy, et al, CLEO Collaboration