Observation of $\psi (3686)\to {\eta }^{\prime }{e}^{+}{e}^{-}$

Abstract

Using a data sample of $448.1\times 10^6$ $\psi (3686)$ events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay $\psi (3686)\to {\eta }^{\prime }{e}^{+}{e}^{-}$, with significances of 7.0$\sigma$ and 6.3$\sigma$ when reconstructing the ${\eta }^{\prime }$ meson via its decay modes ${\eta }^{\prime }\to \gamma {\pi }^{+}{\pi }^{-}$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\eta$ ($\eta \to \gamma \gamma$), respectively. The weighted average branching fraction is determined to be $\mathcal{B}(\psi (3686)\to {\eta }^{\prime }{e}^{+}{e}^{-})=(1.90\pm 0.25\pm 0.11)\times 10^{-6}$, where the first uncertainty is statistical and the second systematic.

10 pages, 3 figures

References in corpus (7)

• Study of the electromagnetic transition form-factors in η-> μ^+μ^-γand ω-> μ^+μ^-π^0 decays with NA60
• Determination of the number of $\psi (3686)$ events at BESIII
• Measurement of the omega -> pi^0 e^+e^- and eta -> e^+e^-g Dalitz decays with the A2 setup at MAMI
• Measurement of the $\varphi \to {\pi }^0{e}^{+}{e}^{-}$ transition form factor with the KLOE detector
• Study of Dalitz decay phi -> eta e+e- with KLOE detector
• Study of electromagnetic decay of $J/\psi$ and ${\psi }^{\prime }$ to vector and pseudoscalar
• Observation of $\psi (3686)\to e^{+}{e}^{-}{\chi }_{cJ}$ and ${\chi }_{cJ}\to e^{+}{e}^{-}J/\psi$

Cited by in corpus (6)

• Study of the electromagnetic Dalitz decays $\psi ({\rm Y})\to {\eta }_c({\eta }_b)l^{+}{l}^{-}$
• Frame dependence of transition form factors in light-front dynamics
• Observation of the double Dalitz decay ${\eta }^{\prime }\to e^{+}{e}^{-}{e}^{+}{e}^{-}$
• Study of the electromagnetic Dalitz decay $J/\psi \to e^{+}{e}^{-}{\pi }^0$
• Observation of the electromagnetic Dalitz decay $D^{\ast 0}\to D^0{e}^{+}{e}^{-}$
• QCD analysis of the $P$-wave charmonium electromagnetic Dalitz decays $h_c\to {\eta }^{(\prime )}{\ell }^{+}{\ell }^{-}$