Observation of ${\eta }^{\prime }\to \omega e^{+}{e}^{-}$

Abstract

Based on a sample of \etapr mesons produced in the radiative decay $J/\psi \to \gamma {\eta }^{\prime }$ in $1.31\times 10^9$ $J/\psi$ events collected with the BESIII detector, the decay ${\eta }^{\prime }\to \omega e^{+}{e}^{-}$ is observed for the first time, with a statistical significance of $8\sigma$. The branching fraction is measured to be $\mathcal{B}({\eta }^{\prime }\to \omega e^{+}{e}^{-})=(1.97\pm 0.34(\text{stat})\pm 0.17(\text{syst}))\times 10^{-4}$, which is in agreement with theoretical predictions. The branching fraction of ${\eta }^{\prime }\to \omega \gamma$ is also measured to be $(2.55\pm 0.03(\text{stat})\pm 0.16(\text{syst}))\times 10^{-2}$, which is the most precise measurement to date, and the relative branching fraction $\frac{\mathcal{B}({\eta }^{\prime }\to \omega e^{+}{e}^{-})}{\mathcal{B}({\eta }^{\prime }\to \omega \gamma )}$ is determined to be $(7.71\pm 1.34(\text{stat})\pm 0.54(\text{syst}))\times 10^{-3}$.

arXiv comment8 pages, 10 figures

References in corpus (9)

• Design and Construction of the BESIII Detector
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Search for hadronic transition ${\chi }_{cJ}\to {\eta }_c{\pi }^{+}{\pi }^{-}$ and observation of ${\chi }_{cJ}\to K\bar{K}\pi \pi \pi$
• Study of ${\chi }_{cJ}$ radiative decays into a vector meson
• Dilepton Spectra from Decays of Light Unflavored Mesons
• Electromagnetic transitions in an effective chiral Lagrangian with the eta-prime and light vector mesons
• eta, eta-prime --> pi+ pi- l+ l- in a chiral unitary approach
• Measurement of ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{\mu }^{+}{\mu }^{-}$

Cited by in corpus (3)

• An overview of $\eta$ and ${\eta }^{\prime }$ decays at BESIII
• Event generators for $\eta /{\eta }^{\prime }$ decays at BESIII
• Observation of the hindered electromagnetic Dalitz decay $\psi (3686)\to e^{+}{e}^{-}{\eta }_c$