Observation of the bremsstrahlung of π-mesons interacting with nuclei

Nuclear force bremsstrahlung of π+-mesons has been observed in a freon bubble chamber in which 80–300 MeV π+-mesons interacted with carbon, fluorine and chlorine nuclei. In the indicated energy range the bremsstrahlung cross section for inelastically and elastically scattered π+-mesons as derived from 20 scattering events was found to be (4.5−2.0+1.2) × 10−27 cm2 per fluorine nucleus. Three cases of bremsstrahlung involved absorption of the π+-mesons by the nucleus; in two cases of bremsstrahlung charge-exchange scattering of π+-mesons on the nucleu occurred. The bremsstrahlung cross sections for these various types of nuclear processes have been computed in the quasiclassical approximation. The values obtained from the formulas satisfactorily agree with the experimental results.