Energy-Dependent Structure in Backward-Hemispherep¯pElastic Scattering and High-Mass Bosons

We have observed a strong backward peak in the differential cross sections of backward-hemisphere $\overline{p}p$ elastic scattering in the momentum range 300-700 MeV/c. The differential cross section near 180° and near 90° shows energy-dependent fluctuations. A consistent interpretation of these fluctuations can be made in terms of direct-channel boson resonances with masses and widths $m_r,{\Gamma }_r$, in MeV, of (∼1925, ∼10) and (1945, ∼20), and a state with mass greater than ∼1975 MeV and width greater than 20 MeV.