Measurement of the proton form factor by studying $e^{+}{e}^{-}\to p\bar{p}$

Abstract

Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of $e^{+}{e}^{-}\to p\bar{p}$ at 12 center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal $(|G_E|=|G_M|)$. In addition, the ratio of electric to magnetic form factors, $|G_E/G_M|$, and $|G_M|$ are extracted by fitting the polar angle distribution of the proton for the data samples with larger statistics, namely at $\sqrt{s}=$ 2232.4 and 2400.0 MeV and a combined sample at $\sqrt{s}$ = 3050.0, 3060.0 and 3080.0 MeV, respectively. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30\%. The $|G_E/G_M|$ ratios are close to unity and consistent with BaBar results in the same $q^2$ region, which indicates the data are consistent with the assumption that $|G_E|=|G_M|$ within uncertainties.

13 pages, 24 figures

References in corpus (3)

• Nucleon electromagnetic form factors from lattice QCD using a nearly physical pion mass
• The electromagnetic form factors of the proton in the timelike region
• Electromagnetic nucleon form factors in instant and point form

Cited by in corpus (23)

• The electromagnetic form factors of the $\Lambda$ in the timelike region
• Study of the process $e^{+}{e}^{-}\to p\bar{p}$ via initial state radiation at BESIII
• Hyperon electromagnetic form factors in the timelike region
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• $N\bar{N}$ production in $e^{+}{e}^{-}$ annihilation near the threshold revisited
• Proton Electromagnetic Form Factors in the Time-like Region through the Scan Technique
• New insights into the oscillation of the nucleon electromagnetic form factors
• Determination of the ${\Sigma }^{+}$ Timelike Electromagnetic Form Factors
• The fourth dimension of the nucleon structure: spacetime analysis of the timelike electromagnetic proton form factors
• Understanding oscillating features of the timelike nucleon electromagnetic form factors within the extending vector meson dominance model
• Improved measurements of two-photon widths of the ${\chi }_{cJ}$ states and helicity analysis for ${\chi }_{c2}\to \gamma \gamma$
• Natural explanation of recent results on $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$
• Study of $e^{+}{e}^{-}\to 2(p\bar{p})$ at center-of-mass energies between 4.0 and 4.6 GeV
• Production of $D^{(\ast )}{\bar{D}}^{(\ast )}$ near the thresholds in $e^{+}{e}^{-}$ annihilation
• The cross section of the process $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ in the vicinity of charmonium $\psi (3770)$ including three-gluon and $D$-meson loop contributions
• Compared analysis of time-like hyperon form factors
• Electromagnetic nucleon form factors in the extended vector meson dominance model
• Observation of $e^{+}{e}^{-}\to pp\bar{p}\bar{n}{\pi }^{-}+c.c.$
• Contribution of the non-resonant mechanism to the double and single differential distributions over the invariant variables in the reaction $e^{+}+e^{-}\to N+\bar{N}+{\pi }^0$
• Coupled-channel analysis of the near-threshold $e^{+}{e}^{-}\to N\bar{N}$ cross sections
• Analytical formula for the cross section of hadron production from $e^{+}{e}^{-}$ collisions around the narrow charmouinum resonances
• Time-like electromagnetic form factors of $\Lambda ,\Sigma$ and ${\Xi }^{+}$ in a light-front quark model
• Baryon Form Factors