Interaction lengths and diffraction scattering of 4.2 GeV π-mesons in G5 emulsion

Abstract
A large block of G5 emulsion has been exposed to the 4.2 Gev π-meson beam of the Berkeley Bevatron and 120 m of π-meson track scanned. The total interaction length is found to be (27.1±2.4) cm and the individual interaction lengths for the production of stars and scatters are (38.7±3.5)cm and (90+28 −15) cm respectively. The geometrical interaction length is 28.4 cm. Good agreement with diffraction scattering theory is found for the observed angular distribution of the secondaries in the elastic scattering events.