Origin of the structures observed in $e^{+}{e}^{-}$ annihilation into multipion states around the $\bar{p}p$ threshold

Abstract

We analyze the origin of the structures observed in the reactions $e^{+}{e}^{-}\to 3({\pi }^{+}{\pi }^{-})$, $2({\pi }^{+}{\pi }^{-}{\pi }^0)$, $\omega {\pi }^{+}{\pi }^{-}{\pi }^0$, and $e^{+}{e}^{-}\to 2({\pi }^{+}{\pi }^{-}){\pi }^0$ around the antiproton-proton ($\bar{p}p$) threshold. We calculate the contribution of the two-step process $e^{+}{e}^{-}\to \bar{N}N\to$ multipions to the total reaction amplitude. The amplitude for $e^{+}{e}^{-}\to \bar{N}N$ is constrained from near-threshold data on the $e^{+}{e}^{-}\to \bar{p}p$ cross section and the one for $\bar{N}N\to$ multipions can be likewise fixed from available experimental information, for all those $5\pi$ and $6\pi$ states. The resulting amplitude for $e^{+}{e}^{-}\to$ multipions turns out to be large enough to play a role for the considered $e^{+}{e}^{-}$ annihilation channels and, in three of the four reactions, even allows us to reproduce the data quantitatively near the $\bar{N}N$ threshold. The structures seen in the experiments emerges then as a threshold effect due to the opening of the $\bar{N}N$ channel.

7 pages, 4 figures

References in corpus (7)

• Three dimensional image correlation from X-Ray computed tomography of solid foam
• 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
• Effects of S-wave thresholds
• Energy-dependent partial-wave analysis of all antiproton-proton scattering data below 925 MeV/c
• On the near-threshold $\bar{p}p$ invariant mass spectrum measured in $J/\psi$ and ${\psi }^{\prime }$ decays
• New structures in the proton-antiproton system

Cited by in corpus (23)

• The electromagnetic form factors of the $\Lambda$ in the timelike region
• General considerations on the nature of $Z_b(10610)$ and $Z_b(10650)$ from their pole positions
• Study of the process $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\eta$ using initial state radiation
• Hyperon electromagnetic form factors in the timelike region
• Observation of a Fine Structure in $e^{+}{e}^{-}\to$ hadrons Production at the Nucleon-antinucleon Threshold
• Semileptonic $B$ and $B_s$ decays involving scalar and axial-vector mesons
• Investigating the role of strangeness in baryon$-$antibaryon annihilation at the LHC
• Real and virtual $N\bar{N}$ pair production near the threshold
• Possible Assignment of Excited Light ${}^3{S}_1$ Vector Mesons
• Fine structure of the cross sections of $e^{+}{e}^{-}$ annihilation near the thresholds of $p\bar{p}$ and $n\bar{n}$ production
• Toy model to understand oscillatory behavior in timelike nucleon form factors
• Interaction of real and virtual $p\bar{p}$ pairs in $J/\psi \to p\bar{p}\gamma (\rho ,\omega )$ decays
• $J/\psi \to \gamma {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ and the structure observed around the $\bar{p}p$ threshold
• Angular distributions in $J/\psi \to p\bar{p}{\pi }^0(\eta )$ decays
• Composite nature of $Z_b$ states from data analysis
• Structure around $p\bar{p}$ threshold in $J/\psi$ radiative decays
• Coupled channels and production of near-threshold $B^{(\ast )}{\bar{B}}^{(\ast )}$ resonances in $e^{+}{e}^{-}$ annihilation
• Common explanation of the behavior of some $e^{+}{e}^{-}$ annihilation processes around $\sqrt{s}$ = 1.9 GeV
• Studying the bound state of the $B\bar{K}$ system in the Bethe-Salpeter formalism
• Meson production in $J/\psi$ decays and $J/\psi \to N\bar{N}\gamma$ process
• Coupled-channel analysis of the near-threshold $e^{+}{e}^{-}\to N\bar{N}$ cross sections
• Testing B-violating signatures from Exotic Instantons in future colliders
• Antiproton-proton interaction and related hadron physics