Observation of the double Dalitz decay ${\eta }^{\prime }\to e^{+}{e}^{-}{e}^{+}{e}^{-}$

Abstract

Based on $(10087\pm 44)\times 10^6$ $J/\psi$ events collected with the BESIII detector at BEPCII, the double Dalitz decay ${\eta }^{\prime }\to e^{+}{e}^{-}{e}^{+}{e}^{-}$ is observed for the first time via the $J/\psi \to \gamma {\eta }^{\prime }$ decay process. The significance is found to be 5.7$\sigma$ with systematic uncertainties taken into consideration. Its branching fraction is determined to be $\mathcal{B}({\eta }^{\prime }\to e^{+}{e}^{-}{e}^{+}{e}^{-})=(4.5\pm 1.0(stat.)\pm 0.5(sys.))\times 10^{-6}$.

References in corpus (7)

• Observation of the Dalitz Decay ${\eta }^{\prime }\to \gamma e^{+}{e}^{-}$
• Modeling interactions of photons with pseudoscalar and vector mesons
• Determination of the Parity of the Neutral Pion via the Four-Electron Decay
• Search for the charged lepton flavor violating decay $J/\psi \to e\tau$
• Search for the rare decays $J/\psi \to D^0{e}^{+}{e}^{-}+c.c.$ and $\psi (3686)\to D^0{e}^{+}{e}^{-}+c.c.$
• Measurement of the absolute branching fractions of Jpsi to gamma eta and eta decay modes
• Measurement of the branching fraction for $\psi (3686)\to \omega K_S^0{K}_S^0$

Cited by in corpus (2)

• Observation of the rare decay of the $\eta$ meson to four muons
• Measurement of the double Dalitz decay $\eta \to e^{+}{e}^{-}{e}^{+}{e}^{-}$