e+e-→Λc+Λc- Cross Sections and the Λc+ Electromagnetic Form Factors within the Extended Vector Meson Dominance Model

Within the extended vector meson dominance model, we investigate the e(+)e(-)->Lambda(c)+Lambda b(c)(-) reaction and the electromagnetic form factors of the charmed baryon Lambda(+)(c) . The model parameters are determined by fitting them to the cross sections of the process e(+)e(-)->Lambda(+)(c)Lambda(- )(c)and the magnetic form factor |G (M)| of Lambda(+)(c) . By considering four charmonium-like states, called psi(4500), psi(4660), psi(4790), and psi(4900), we can well describe the current data on the e(+)e(-)->Lambda(+)(c)Lambda(-)( c) reaction from the reaction threshold up to 4.96 GeV. In addition to the total cross sections and |G (M)|, the ratio |G (E)/G( M)| and the effective form factor |G e(ff)| for Lambda(+)(c) are also calculated, and found that these calculations are consistent with the experimental data. Within the fitted model parameters, we have also estimated the charge radius of the charmed Lambda(+)(c) baryon.