The electromagnetic form factors of $\Lambda$ hyperon in $e^+e^-\rightarrow \bar\Lambda\Lambda$

Understand

We study the electromagnetic form factors of $\Lambda$ hyperon in the timelike region using the recent experimental data in the exclusive production of $\bar{\Lambda} \Lambda$ pair in electron-position annihilation.

• We present a pQCD inspired parametrization of $G_E(s)$ and $G_M(s)$ with only two parameters, and we consider a suppression mechanism of the electric form factor $G_E(s)$ compared to the magnetic form factor $G_M(s)$.
• The parameters are determined through fitting our parametrization to the effective form factor data in the reaction $e^+e^-\rightarrow \bar\Lambda\Lambda$.
• Except the threshold region, our parametrization can reproduce satisfactorily the known behavior of the existing data from the BarBar, DM2 and BESIII Collaborations.