Search for C-parity violation in $J/\psi \to \gamma \gamma$ and $\gamma \varphi$

Abstract

Using $1.06\times 10^8$ $\psi (3686)$ events recorded in $e^{+}{e}^{-}$ collisions at $\sqrt{s}=$ 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in $J/\psi \to \gamma \gamma$ and $\gamma \varphi$ decays via $\psi (3686)\to J/\psi {\pi }^{+}{\pi }^{-}$. No significant signals are observed in either channel. Upper limits on the branching fractions are set to be $\mathcal{B}(J/\psi \to \gamma \gamma )<2.7\times 10^{-7}$ and $\mathcal{B}(J/\psi \to \gamma \varphi )<1.4\times 10^{-6}$ at the 90\% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.

7 pages, 2 figures

References in corpus (1)

• Search for the C-parity violating process J/psi->gamma gamma via psi(2S)->pi+pi- J/psi