Study of electromagnetic Dalitz decays ${\chi }_{cJ}\to {\mu }^{+}{\mu }^{-}J/\psi$

Abstract

Using $4.48\times 10^8$ $\psi (3686)$ events collected with the BESIII detector, we search for the decays ${\chi }_{cJ}\to {\mu }^{+}{\mu }^{-}J/\psi$ through the radiative decays $\psi (3686)\to \gamma {\chi }_{cJ}$, where $J=0,1,2$. The decays ${\chi }_{c1,2}\to {\mu }^{+}{\mu }^{-}J/\psi$ are observed, and the corresponding branching fractions are measured to be $\mathcal{B}({\chi }_{c1}\to {\mu }^{+}{\mu }^{-}J/\psi )=(2.51\pm 0.18\pm 0.20)\times 10^{-4}$ and $\mathcal{B}({\chi }_{c2}\to {\mu }^{+}{\mu }^{-}J/\psi )=(2.33\pm 0.18\pm 0.29)\times 10^{-4}$, where the first uncertainty is statistical and the second one systematic. No significant ${\chi }_{c0}\to {\mu }^{+}{\mu }^{-}J/\psi$ decay is observed, and the upper limit on the branching fraction is determined to be $2.0\times 10^{-5}$ at 90% confidence level. Also, we present a study of di-muon invariant mass dependent transition form factor for the decays ${\chi }_{c1,2}\to {\mu }^{+}{\mu }^{-}J/\psi$.

References in corpus (13)

• 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 ${\chi }_{cJ}\to K\bar{K}\pi \pi \pi$
• Dilepton Spectra from Decays of Light Unflavored Mesons
• Determination of the number of $\psi (3686)$ events at BESIII
• Observation of $e^{+}{e}^{-}\to \omega {\chi }_{c1,2}$ near $\sqrt{s}$ = 4.42 and 4.6 GeV
• Study of the electromagnetic transitions $J/\psi \to P{l}^{+}{l}^{-}$ and probe dark photon
• Probing Dark force at BES-III/BEPCII
• ${\chi }_{c1}$ and ${\chi }_{c2}$ resonance parameters with the decays ${\chi }_{c1,c2}\to J/\psi {\mu }^{+}{\mu }^{-}$
• Observation of $\psi (3686)\to e^{+}{e}^{-}{\chi }_{cJ}$ and ${\chi }_{cJ}\to e^{+}{e}^{-}J/\psi$
• Observation of $h_c$ radiative decay $h_c\to \gamma {\eta }^{\prime }$ and evidence for $h_c\to \gamma \eta$
• Muon Pair Production in Radiative Decays of Heavy Quarkonia

Cited by in corpus (4)

• Cross section measurement of $e^{+}{e}^{-}\to {\eta }^{\prime }J/\psi$ from $\sqrt{s}=4.178$ to $4.600$ GeV
• Prospects for quarkonium studies at the high-luminosity LHC
• QCD analysis of the $P$-wave charmonium electromagnetic Dalitz decays $h_c\to {\eta }^{(\prime )}{\ell }^{+}{\ell }^{-}$
• Inclusive charged and neutral particle multiplicity distributions in ${\chi }_{cJ}$ and $J/\psi$ decays