First Observation of a Three-Resonance Structure in $e^{+}{e}^{-}\to$Nonopen Charm Hadrons

Abstract

We report the measurement of the inclusive cross sections for $e^{+}{e}^{-}$$\to$nOCH (where nOCH denotes non-open charm hadrons) with improved precision at center-of-mass (c.m.) energies from 3.645 to 3.871 GeV. We observe three resonances: $\mathcal{R}(3760)$, $\mathcal{R}(3780)$, and $\mathcal{R}(3810)$ with significances of $8.1\sigma$, $13.7\sigma$, and $8.8\sigma$, respectively. The $\mathcal{R}(3810)$ state is observed for the first time, while the $\mathcal{R}(3760)$ and $\mathcal{R}(3780)$ states are observed for the first time in the nOCH cross sections. Two sets of resonance parameters describe the energy-dependent line shape of the cross sections well. In set I [set II], the $\mathcal{R}(3810)$ state has mass $(3805.7\pm 1.1\pm 2.7)$ [$(3805.7\pm 1.1\pm 2.7)$] MeV/$c^2$, total width $(11.6\pm 2.9\pm 1.9)$ [$(11.5\pm 2.8\pm 1.9)$] MeV, and an electronic width multiplied by the nOCH decay branching fraction of $(10.9\pm 3.8\pm 2.5)$ [$(11.0\pm 3.4\pm 2.5)$] eV. In addition, we measure the branching fractions $\mathcal{B}[\mathcal{R}(3760)$$\to$nOCH$]=(25.2\pm 16.1\pm 30.4)\%[(6.4\pm 4.8\pm 7.7)\%]$ and $\mathcal{B}[\mathcal{R}(3780)$$\to$nOCH$]=(12.3\pm 6.6\pm 8.3)\%[(10.4\pm 4.8\pm 7.0)\%]$ for the first time. The $\mathcal{R}(3760)$ state can be interpreted as an open-charm (OC) molecular state, but containing a simple four-quark state component. The $\mathcal{R}(3810)$ state can be interpreted as a hadrocharmonium state.

References in corpus (27)

• Observation of a New Narrow Charmonium State in Exclusive B+-->K+ pi+pi- J/psi Decays
• Observation of a narrow charmonium-like state in exclusive B+ -> K+ pi+pi- J/psi decays
• Heavy quarkonium: progress, puzzles, and opportunities
• Design and Construction of the BESIII Detector
• Observation of a charged charmoniumlike structure in e+e- to pi+pi-J/psi at \sqrt{s}=4.26 GeV
• Observation of a Broad Structure in the ${\pi }^{+}{\pi }^{-}J/\psi$ Mass Spectrum around 4.26 GeV/$c^2$
• Observation of a charged charmoniumlike structure Z_c(4020) and search for the Z_c(3900) in e+e- to pi+pi-h_c
• Observation of Two Resonant Structures in e+e- to pi+ pi- psi(2S) via Initial State Radiation at Belle
• The D*0 D0bar threshold resonance
• Evidence of a Broad Structure at an Invariant Mass of 4.32 GeV/$c^2$ in the Reaction $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\psi (2S)$ Measured at BaBar
• Hadro-Charmonium
• Precise measurement of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}J/\psi$ cross section at center-of-mass energies from 3.77 to 4.60 GeV
• Charmonium Decays of $Y(4260), psi(4160), and psi(4040)
• Observation of $e^{+}{e}^{-}\to \gamma X(3872)$ at BESIII
• Confirmation of the Y(4260) Resonance Production in ISR
• Evidence of Two Resonant Structures in $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{h}_c$
• Matching perturbative and Parton Shower corrections to Bhabha process at flavour factories
• Measurement of the near-threshold $e^{+}{e}^{-}\to D\bar{D}$ cross section using initial-state radiation
• Study of the Exclusive Initial-State Radiation Production of the $D\bar{D}$ System
• Measurements of the cross sections for $e^{+}{e}^{-}\to \mathrm{hadrons}$ at 3.650, 3.6648, 3.773 GeV and the branching fraction for $\psi (3770)\to \mathrm{non}-D\bar{D}$
• Measurements of the braching fractions for psi(3770)--> D0D0-bar,D+D-,DD-bar$ and the resonance parameters of psi(3770) and psi(2S)
• Photon pair production at flavour factories with per mille accuracy
• Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-
• Measurement of cross sections for $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$ at center-of-mass energies from 3.80 to 4.60 GeV
• A Monte Carlo Generator for Full Simulation of e+e- to hadrons Cross section Scan Experiment
• Diresonance in production and scattering of heavy mesons
• Observation of di-structures in $e^{+}{e}^{-}\to J/\psi \mathrm{X}$ at center-of-mass energies around 3.773 GeV

Cited by in corpus (4)

• Global coupled-channel analysis of $e^{+}{e}^{-}\to c\bar{c}$ processes in $\sqrt{s}=3.75-4.7$ GeV
• $\mathcal{R}(3780)$ Resonance Interpreted as the $1^3{D}_1$-Wave Dominant State of Charmonium from Precise Measurements of the Cross Section of $e^{+}{e}^{-}\to$ Hadrons
• Unified coupled-channel description for the five near-threshold structures $\psi (3770)$, $G(3900)$, $R(3760)$, $R(3780)$ and $R(3810)$ from $e^{+}{e}^{-}$ annihilation
• Systematic analysis of the D-wave charmonium states with the QCD sum rules