Coupled-channel analysis of the near-threshold $e^{+}{e}^{-}\to N\bar{N}$ cross sections

Abstract

The possible existence of nucleon-antinucleon bound states has been studied for decades. We investigate the $e^{+}{e}^{-}\to p\bar{p}$ and $e^{+}{e}^{-}\to n\bar{n}$ cross sections in the nonrelativistic effective field theory framework. The proton-antiproton and neutron-antineutron coupled-channel final state interactions are considered and found responsible for near-threshold enhancements. Both the proton-neutron mass difference and the Coulomb interaction between $p$ and $\bar{p}$ are considered, and the $N\bar{N}$ strong interactions are taken into account through a short-distance optical potential. By fitting the low energy constants in the amplitudes to the data for the near-threshold $e^{+}{e}^{-}\to N\bar{N}$ cross sections from the BESIII and SND Collaborations, a $N\bar{N}$ quasi-bound state is found just above the $p\bar{p}$ threshold, and another $N\bar{N}$ pole is found on the unphysical Riemann sheet, farther away from the threshold. The constructed coupled-channel amplitude with Coulomb effects also offers a framework that can be used directly in experimental analyses on fine structures near the $N\bar{N}$ thresholds.

19 pages, 9 figures. To appear in Phys. Rev. D

References in corpus (21)

• Explaining the Many Threshold Structures in the Heavy-Quark Hadron Spectrum
• New Features in the Electromagnetic Structure of the Neutron
• The electromagnetic form factors of the proton in the timelike region
• Study of the process $e^{+}{e}^{-}\to n\bar{n}$ at the VEPP-2000 $e^{+}{e}^{-}$ collider with the SND detector
• Study of psi(2S) Decays to gamma p bar{p}, pi^0 p bar{p} and eta p bar{p} and Search for p bar{p} Threshold Enhancements
• Measurement of the proton form factor by studying $e^{+}{e}^{-}\to p\bar{p}$
• Study of the decay mechanism for B+ to p pbar K+ and B+ to p pbar pi+
• Measurement of proton electromagnetic form factors in the time-like region using initial state radiation at BESIII
• Energy-dependent partial-wave analysis of all antiproton-proton scattering data below 925 MeV/c
• On the strong energy dependence of the e^+e^- to ppbar amplitude near threshold
• On the near-threshold $\bar{p}p$ invariant mass spectrum measured in $J/\psi$ and ${\psi }^{\prime }$ decays
• Study of the process $e^{+}{e}^{-}\to p\bar{p}$ via initial state radiation at BESIII
• Rescattering Effect and Near Threshold Enhancement of $p\bar{p}$ System
• $N\bar{N}$ production in $e^{+}{e}^{-}$ annihilation near the threshold revisited
• Observation of the Anomalous Shape of $X(1840)$ in $J/\psi \to \gamma 3({\pi }^{+}{\pi }^{-})$ Indicating a Second Resonance Near $p\bar{p}$ Threshold
• A possible mechanism for producing the threshold enhancement in $J/\psi \to \gamma p\bar{p}$
• $N\bar{N}$ Scattering at NLO Order in An Effective Theory
• $D^{+}{D}^{-}$ hadronic atom and its production in $pp$ and $p\bar{p}$ collisions
• Understanding oscillating features of the timelike nucleon electromagnetic form factors within the extending vector meson dominance model
• Reexamination of antinucleon-nucleon interactions in covariant chiral effective field theory
• Protonium: Discovery and Prediction

Cited by in corpus (1)

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