(πsup(+), 4He) inelastic interaction at 110 and 160 MeV

The letter presents the results of an experiment with positive pions on 4He, involving the process πsup(+)+4 He→πsup(+)+2p+2n and πsup(+)+4He→πdeg+p+3He, for pion energy at about 110 MeV and 160 MeV. Differential cross-sections of the reactions vs. the laboratory angle of the scattered pion are reported. The general agreement between the experimental data and calculations shows that an interaction model based upon the impulse approximation gives a raw but satisfactory interpretation of the data