Observation of resonance-like behavior of the

The pp → {pp}sπ0 reaction, where {pp}s denotes a diproton, i.e. an unbound interacting proton pair in the 1S0 state, has been studied in order to obtain the forward differential cross section dσ/dΩ at 11 energy values in the region of 0.8–2.8 GeV. A resonance-like peak with the energy E0 = 2.647 ± 0.005 GeV and the width Γ = 0.26 ± 0.03 GeV has been observed in the energy dependence of the differential cross section dσ/dΩ at zero angle. The slope of the angular dependence for the energies in the peak region is different compared with the energies around it. Possible implications on this phenomenon are discussed