Search for the decay eta ' -> gamma gamma eta

Abstract

Using a data sample of 1.31 x 10(9) J/psi events collected with the BESIII detector, a search for eta' -> gamma gamma eta via J/psi ->gamma eta' is performed for the first time. No significant eta' signal is observed in the gamma gamma eta invariant mass spectrum, and the branching fraction of eta' -> gamma gamma eta is determined to be less than 1.33 x 10(-4) at the 90% confidence level.