EVIDENCE FOR THE EXISTENCE OF A BOUND-STATE IN THE PPBAR SYSTEM

We consider two characteristics of the proton-antiproton interaction: rho-(s) = Re F(ppBAR)(s)/Im F(ppBAR)(s) and sigma-tot (s). As a theoretical basis we use the analytic properties of the forward elastic scattering amplitude F(ppBAR)(s). We have analyzed the experimental data on rho and sigma-tot for p(L) < 1 GeV/c. A satisfactory description of rho and sigma-tot in this energy range can be obtained only on the assumption that there exists a quasinuclear state of the ppBAR system with mass close to 2m.