Search for rare decay $J/ \psi \to \phi e^+ e^-$

Abstract

Using a data sample of 448.1×106 ψ(3686) events collected at s = 3.686 GeV with the BESIII detector at the BEPCII, we search for the rare decay J/ψ→ϕe+e− via ψ(3686)→π+π−J/ψ. No signal events are observed and the upper limit on the branching fraction is set to be B(J/ψ→ϕe+e−)<1.2×10−7 at the 90% confidence level, which is still about one order of magnitude higher than the Standard Model prediction.