The electromagnetic form factors of Λ hyperon in e+e−→Λ̄Λ

Abstract

We study the electromagnetic form factors of [Formula: see text] hyperon in the time-like region using the experimental data in the exclusive production of [Formula: see text] pair in electron–positron annihilation. We present a pQCD inspired parametrization of [Formula: see text] and [Formula: see text] with only two parameters, and we consider a suppression mechanism of the electric form factor [Formula: see text] compared to the magnetic form factor [Formula: see text]. The parameters are determined through fitting our parametrization to the data of the effective form factor [Formula: see text] from the DM2, BaBar and BESIII Collaborations in the reaction [Formula: see text]. We use the parametrizations for [Formula: see text] and [Formula: see text] to calculate the Born cross-sections as well as the ratio [Formula: see text]. Except the threshold region, our parametrization can describe the known behavior of the existing data of effective form factor, Born cross-section and the ratio [Formula: see text] from the BaBar, DM2 and BESIII Collaborations. We also predict the double spin polarization observables [Formula: see text], [Formula: see text] and [Formula: see text] in [Formula: see text] which could provide more information on the size of the lambda EMFFs as well as their phase angles.