Search for rare decay $J/\psi \to \varphi e^{+}{e}^{-}$

Abstract

Using a data sample of $448.1\times 10^6$ $\psi (3686)$ events collected at $\sqrt{s}=$ 3.686 GeV with the BESIII detector at the BEPCII, we search for the rare decay $J/\psi \to \varphi e^{+}{e}^{-}$ via $\psi (3686)\to {\pi }^{+}{\pi }^{-}J/\psi$. No signal events are observed and the upper limit on the branching fraction is set to be $\mathcal{B}(J/\psi \to \varphi e^{+}{e}^{-})<1.2\times 10^{-7}$ at the 90\% confidence level, which is still about one order of magnitude higher than the Standard Model prediction.

7 pages, 3 figures