Unitary and analytic model of nucleon EM structure, the puzzle with JLab proton polarization data and new insight into proton charge distribution

Abstract

The Unitary and analytic model of nucleon electromagnetic structure, describing all existing nucleon form factor data, is briefly reviewed. Then in the framework of this model the problem of inconsistency of older proton electric form factor data in space-like region (obtained from process by the Rosenbluth technique) with recent Jefferson Lab data on the ratio $G_{Ep}(t)/G_{Mp}(t)$ (measured in precise polarization ${\overrightarrow{e}}^{-}p\to e^{-}\overrightarrow{p}$ experiment) is suggested to be solved in favour of the latter data which, however, unlike older data cause an existence of the form factor zero, i.e. a difraction minimum in $|G_{Ep}(t)|$ around $t=-Q^2=-13$GeV${}^2$. The new behaviour of $G_{Ep}(t)$ with the zero gives modified proton charge distribution with enlarged value of the mean square charge radius.

9 pages, 11 eps figures. Talk presented at the workshop on Lepton Scattering and the Structure of Hadrons and Nuclei, Erice (Italy), September 2004

References in corpus (3)

• How to reconcile the Rosenbluth and the polarization transfer method in the measurement of the proton form factors
• Nucleon electromagnetic structure revisited
• Universal description of S-wave meson spectra in a renormalized light-cone QCD-inspired model

Cited by in corpus (11)

• Final Analysis of Proton Form Factor Ratio Data at ${\mathbf{Q}}^2=4.0$, 4.8 and 5.6 GeV${}^2$
• Nucleon Polarizabilities: from Compton Scattering to Hydrogen Atom
• Periodic interference structures in the time-like proton form factor
• Phenomenological analysis of near threshold periodic modulations of the proton timelike form factor
• Probing the internal structure of baryons
• The fourth dimension of the nucleon structure: spacetime analysis of the timelike electromagnetic proton form factors
• Antiproton-nucleus electromagnetic annihilation as a way to access the proton timelike form factors
• Numerical values of $f^F$, $f^D$, $f^S$ coupling constants in $SU(3)$ invariant interaction Lagrangian of vector-meson nonet with $1/2^{+}$ octet baryons
• Polarisation observables in lepton antilepton to proton antiproton reactions including lepton mass
• Phenomenological insight into JLab proton polarization data puzzle by deuteron impulse approximation
• Soft rescattering in the timelike proton form factor within a spacetime scheme