The $Σ$ and $Ξ$ electromagnetic form factors in the extended vector meson dominance model

Abstract

We propose a phenomenological extended vector meson dominance model for the baryon electromagnetic structure, and it is found that the current experimental data on the Σ and Ξ electromagnetic form factors in the time-like region can be well described. Meanwhile, we can also reproduce the ratios of the total cross sections of reactions e + e − → Σ + Σ− , Σ 0 Σ0 , and Σ − Σ+ , which are 9.7 ± 1.3 : 3.3 ± 0.7 : 1 at center-of-mass energies from 2.3864 to 3.02 GeV. We also analytically continue the expression of the form factors to spacelike region and estimate the charge radii of the Σ and Ξ hyperons. The result for the Σ − is in agreement with the experimental date.

Measurement of Λ transverse polarization in e+e− collisions at $$ \sqrt{s} $$ = 3.68 − 3.71 GeV

“…The advantage is that their weak parity-violating decay gives straightforward access to the polarization. The timelike form factors are related to more intuitive quantities such as charge and magnetization densities by dispersion relations [8,9]. The production of spin-1/2 baryon-anti-baryon pairs from e + e − collisions is described by two independent parameters, the electric form factor G E and the magnetic form factor G M [10,11].…”

Measurement of Born cross section of $$ {e}^{+}{e}^{-}\to {\Sigma}^{+}{\overline{\Sigma}}^{-} $$ at center-of-mass energies between 3.510 and 4.951 GeV

“…The overpopulation of structures in this mass region and the mismatch of the properties between the potential model predictions and experimental measurements make them good candidates for exotic states. Many hypotheses have been proposed to explain their nature [2,[16][17][18][19][20][21][22][23], including the possibility of being hybrid states, multiple-quark states, or even molecular structures. In particular, charmless decays of these non-conventional states are proposed by the hybrid JHEP05(2024)022 model [16].…”