Initial state radiation in $e^+e^-$ annihilation

In two earlier papers it was demonstrated that Lorentzian and Galilean symmetries could both be useful in the analysis of the annihilation reaction $e^+ e^- \to \gamma \Lambda(\rightarrow p\pi^-) \bar{\Lambda}(\rightarrow \bar{p}\pi^+)$. It was also demonstrated that any pair of hyperon form factors would be acceptable, but that the $\{G_E, G_M\}$ pair would probably be the simplest one to handle.