Search for $\eta_{c}^{\prime}$ decays into vector meson pairs
  The processes $\etacpto \rho^{0}\rho^{0}$, $K^{*0}\bar{K}^{*0}$, and $\phi\phi$ are searched for using a sample of $1.06 \times 10^8$ $\psip$ events collected with the BESIII detector at the BEPCII collider. No signals are observed in any of the three final states. The upper limits on the decay branching fractions are determined to be $\mathcal{B}(\etacpto\rho^{0}\rho^{0})<3.1\times10^{-3}$, $\mathcal{B}(\etacpto K^{*0}\bar{K}^{*0})<5.4 \times10^{-3}$, and $\mathcal{B}(\etacpto\phi\phi)<2.0\times10^{-3}$ at the 90% confidence level. The upper limits are lower than the existing theoretical predictions. 
The BESIII Collaboration
hep-ex