Observation of the electromagnetic Dalitz decay $D^{\ast 0}\to D^0{e}^{+}{e}^{-}$

Abstract

Based on 3.19 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data accumulated at the center-of-mass energy 4.178 GeV with the BESIII detector operating at the BEPCII collider, the electromagnetic Dalitz decay $D^{\ast 0}\to D^0{e}^{+}{e}^{-}$ is observed for the first time with a statistical significance of $13.2\sigma$. The ratio of the branching fraction of $D^{\ast 0}\to D^0{e}^{+}{e}^{-}$ to that of $D^{\ast 0}\to D^0\gamma$ is measured to be $(11.08\pm 0.76\pm 0.49)\times 10^{-3}$. By using the world average value of the branching fraction of $D^{\ast 0}\to D^0\gamma$, the branching fraction of $D^{\ast 0}\to D^0{e}^{+}{e}^{-}$ is determined to be $(3.91\pm 0.27\pm 0.17\pm 0.10)\times 10^{-3}$, where the first uncertainty is statistical, the second systematic and the third external branching fractions.

References in corpus (12)

• 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
• Future Physics Programme of BESIII
• Branching fraction measurements of χ_{c0} and χ_{c2} to π^0π^0 and ηη
• Nucleon Resonances with Hidden Charm in $\gamma p$ reactions
• 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
• Observation of $\psi (3686)\to e^{+}{e}^{-}{\chi }_{cJ}$ and ${\chi }_{cJ}\to e^{+}{e}^{-}J/\psi$
• Observation of $\psi (3686)\to {\eta }^{\prime }{e}^{+}{e}^{-}$
• Tests of the Atomki anomaly in lepton pair decays of heavy mesons
• Observation of the Dalitz Decay $D_s^{\ast +}\to D_s^{+}{e}^{+}{e}^{-}$

Cited by in corpus (2)

• Observation of the hindered electromagnetic Dalitz decay $\psi (3686)\to e^{+}{e}^{-}{\eta }_c$
• Probing the ATOMKI X17 vector boson using Dalitz decays $V\to P{e}^{+}{e}^{-}$