Search

First results on π−d → are reported. The measurements were made using 8 specially designed neutron counters, which were carefully calibratedin situ. The differential cross sections atTπ=142, 180, 217, and 254 MeV were obtained at four angles between 0° and 90°, they are compared to π+d →pp data measured at the same energies and angles with the same setup. At every beam energy, the shape of the angular distributions of π−d →nn and π+d →pp is the same to ±2%. The absolute cross sections differ by 1 to 10%. The error in this comparison is ±4% implying a small violation of charge symmetry.

Crystal Ball Collaboration results concerning π0π0 and η production on hydrogen and 3 nuclear targets are reported. A possible existence of a σ-resonance, medium effects and final state interactions are subjects of this contribution.