Observation of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\psi (3770)$ and $D_1(2420{)}^0{\bar{D}}^0+c.c.$

Abstract

Several intermediate states of the reaction channels $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{D}^0{\bar{D}}^0$ and $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{D}^{+}{D}^{-}$ are studied using the data samples collected with the BESIII detector at center-of-mass energies above 4.08 GeV. For the first time in this final state, a $\psi (3770)$ signal is seen in the $D\bar{D}$ invariant mass spectrum, with a statistical significance of $5.2\sigma$ at $\sqrt{s}=4.42$ GeV. There is also evidence for this resonance at $\sqrt{s}$ = 4.26 and 4.36 GeV with statistical significance of 3.2$\sigma$ and 3.3$\sigma$, respectively. In addition, the Born cross section of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\psi (3770)$ is measured. The proposed heavy-quark-spin-symmetry partner of the $X(3872)$, the state $X_2(4013)$, is also searched for in the $D\bar{D}$ invariant mass spectra. No obvious signal is found. The upper limit of the Born cross section of the process $e^{+}{e}^{-}\to {\rho }^0{X}_2(4013)$ combined with the branching fraction is measured. Also, the processes $e^{+}{e}^{-}\to D_1(2420)\bar{D}+c.c.$ are investigated. The neutral mode with $D_1(2420{)}^0\to D^0{\pi }^{+}{\pi }^{-}$ is reported with statistical significance of 7.4$\sigma$ at $\sqrt{s}=4.42$ GeV for the first time, and evidence with statistical significance of 3.2$\sigma$ and 3.3$\sigma$ at $\sqrt{s}$ = 4.36 and 4.60 GeV is seen, respectively. No evident signal for the process $e^{+}{e}^{-}\to D_1(2420{)}^0{\bar{D}}^0+c.c.,D_1(2420{)}^0\to D^{\ast +}{\pi }^{-}$ is reported. Evidence for $e^{+}{e}^{-}\to D_1(2420{)}^{+}{D}^{-}+c.c.,D_1(2420{)}^{+}\to D^{+}{\pi }^{+}{\pi }^{-}$ is reported with statistical significance of 3.1$\sigma$ and 3.0$\sigma$ at $\sqrt{s}$ = 4.36 and 4.42 GeV, respectively.

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• Heavy quarkonium: progress, puzzles, and opportunities
• Observation of Two Resonant Structures in e+e- to pi+ pi- psi(2S) via Initial State Radiation at Belle
• Measurement of e^+e^- to pi^+pi^-J/psi Cross Section via Initial State Radiation at Belle
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• The Heavy Quark Spin Symmetry Partners of the X(3872)
• The XYZ states revisited
• Observation of the $\psi (1^3{D}_2)$ state in $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\gamma {\chi }_{c1}$ at BESIII
• Evidence for η_{c}(2S) in ψ(3686) \to γK_{S}^{0}K^{\pm}π^{\mp}π^{+}π^{-}

Cited by in corpus (7)

• Prediction of an exotic state around 4240 MeV with $J^{PC}=1^{-+}$ as C-parity partner of Y(4260) in molecular picture
• Observation of resonance structures in $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\psi }_2(3823)$ and mass measurement of ${\psi }_2(3823)$
• Spectrum of the molecular tetraquarks: Unraveling the $T_{cs0}(2900)$ and $T_{c\bar{s}0}^a(2900)$
• Measurement of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{D}^{+}{D}^{-}$ cross sections at center-of-mass energies from 4.190 to 4.946 GeV
• Colloquium: Hadron Production in Open-charm Meson Pair at $e^{+}{e}^{-}$ Collider
• Study of $e^{+}{e}^{-}\to D^{+}{D}^{-}{\pi }^{+}{\pi }^{-}$ at center-of-mass energies from 4.36 to 4.60 GeV
• Looking for a vector charmonium-like state $Y$ in $e^{+}{e}^{-}\to \bar{D}{D}_1(2420)+c.c.$