Search for η c Decays into ππ and KK̄

Using 58 million J/ψ events taken with the BESII detector, a search for ηc CP violating decays into ππ and KK̄ has been performed. No clear ηc signal is observed, and upper limits for B(ηc → ππ) and B(ηc → KK̄) are given at the 90% confidence level, B(J/ψ → γηc) · B(ηc → π π) < 1.1 × 10, B(J/ψ → γηc) · B(ηc → π π) < 0.71 × 10, B(J/ψ → γηc) · B(ηc → K K) < 0.96 × 10 and B(J/ψ → γηc) ·B(ηc → K 0 SK 0 S) < 0.53 × 10 . a Current address: Iowa State University, Ames, IA 500113160, USA b Current address: Purdue University, West Lafayette, IN 47907, USA c Current address: Cornell University, Ithaca, NY 14853, USA d Current address: Laboratoire de l’Accélératear Linéaire, Orsay, F-91898, France 2 M. Ablikim et al.: Search for ηc Decays into ππ and KK̄