On the electromagnetic form factors of hadrons in the time-like region near threshold

Hadron electromagnetic form factor in the time-like region at the boundary of the physical region is considered. The energy behavior of the form factor is shown to be determined by the strong hadron–antihadron interaction. We propose a simple phenomenological model of the interaction that describes the form factor behaviour in the region where scattering length approximation fails and estimate on its basis imaginary part of the scattering lengths (volumes) for , , and from present experimental data. The developed approach enables us to analyze the existence of baryon–antibaryon () near threshold resonances. The experiments to extract detailed information on the near threshold interaction from hadron form factor energy behavior are suggested.