Timelike nucleon electromagnetic form factors: All about interference of isospin amplitudes

Abstract

A striking feature of the timelike nucleon electromagnetic form factors, investigated in $e^{+}{e}^{-}\to N\bar{N}$ annihilation reactions, is the modulation by local structures of small magnitude and oscillatory form, showing up above $N\bar{N}$ threshold. Starting from an isospin decomposition of the proton and neutron form factors it is shown that such structures are the natural consequence of the interference of a large and a small amplitudes, resulting in a sinusoidal behavior as a function of the "invariant energy" if the relative phase shift varies with energy. Thus, periodic oscillations superimposed on a smooth background will be observed. In this scenario, an equal size of the modulation for neutron and proton discovered by recent BESIII data evidently implies the particular isoscalar or isovector nature of these local structures, or their orthogonal interference, hence specifies their origin as excited vector mesons whose widths are tied to the modulation frequency.We clarify that the phase difference of modulation between neutron and proton as BESIII data found, but not the modulation itself, is the evidence of an imaginary part of the timelike nucleon electromagnetic form factors, which is associated with the rescattering processes.

arXiv comment7 pages, 2 figures

References in corpus (30)

• A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector
• Theory of deeply virtual Compton scattering on the nucleon
• Electron-Ion Collider in China
• Dispersion analysis of the nucleon form factors including meson continua
• Study of e+e- --> p anti-p via initial-state radiation at BABAR
• Study of e+e- --> Lambda anti-Lambda, Lambda anti-Sigma0, Sigma0 anti-Sigma0 using Initial State Radiation with BABAR
• Proton and neutron electromagnetic form factors from lattice QCD
• Measurement of proton electromagnetic form factors in $e^{+}{e}^{-}\to p\bar{p}$ in the energy region 2.00-3.08 GeV
• New insights into the nucleon's electromagnetic structure
• The electromagnetic form factors of the proton in the timelike region
• Nucleon Electromagnetic Form Factors in the Timelike Region
• Measurement of the e+e- --> p anti-p cross section in the energy range from 3.0 to 6.5 GeV
• Periodic interference structures in the time-like proton form factor
• Nucleon electromagnetic form factors and polarization observables in space-like and time-like regions
• Space-like and time-like pion electromagnetic form factor and Fock state components within the Light-Front dynamics
• Electromagnetic Form Factors of the SU(3) Octet Baryons in the semibosonized SU(3) Nambu-Jona-Lasinio Model
• Measurements of Sigma+ and Sigma- Time-like Electromagnetic Form Factors for center-of-mass energies from 2.3864 to 3.0200 GeV
• Time- and Spacelike Nucleon Electromagnetic Form Factors beyond Relativistic Constituent Quark Models
• High-precision determination of the electric and magnetic radius of the proton
• Observation of a resonant structure in $e^{+}{e}^{-}\to K^{+}{K}^{-}{\pi }^0{\pi }^0$
• New structures in the proton-antiproton system
• Measurement of cross section for $e^{+}{e}^{-}\to {\Xi }^0{\bar{\Xi }}^0$ near threshold
• Phenomenological analysis of near threshold periodic modulations of the proton timelike form factor
• New fit of time-like proton electromagnetic form factors from $e^{+}{e}^{-}$ colliders
• Measurement of the cross section for $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ and evidence of the decay $\psi (3770)\to \Lambda \bar{\Lambda }$
• Study of $e^{+}{e}^{-}\to p\bar{p}$ in the vicinity of $\psi (3770)$
• Vector mesons and electromagnetic form factor of the $\Lambda$ hyperon
• Light unflavor vector meson spectroscopy around the mass range of $2.4\sim 3$ GeV and possible experimental evidence
• On Electron-Positron Annihilation into Nucleon-Antinucleon Pairs
• Fine structure of the cross sections of $e^{+}{e}^{-}$ annihilation near the thresholds of $p\bar{p}$ and $n\bar{n}$ production

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• New insights into the oscillation of the nucleon electromagnetic form factors
• Understanding oscillating features of the timelike nucleon electromagnetic form factors within the extending vector meson dominance model
• Compared analysis of time-like hyperon form factors
• The electromagnetic form factors and spin polarization of ${\Lambda }_c^{+}$ in the process $e^{+}{e}^{-}\to {\Lambda }_c^{+}{\bar{\Lambda }}_c^{-}$
• Measurement of ${\Sigma }^{+}$ transverse polarization in $e^{+}{e}^{-}$ collisions at $\sqrt{s}=3.68-3.71$ GeV
• Accessing baryon-antibaryon generalized distribution amplitudes in $e^{\pm }\gamma \to e^{\pm }B\bar{B}$