Characteristics of π^--nucleon collisions at a primary energy of 4·4 gev

Abstract

Eight hundred and sixteen nuclear interactions produced by 4·4 GeV π^--mesons in nuclear emulsion have been obtained by "along the track" scanning procedure. Favourable secondary particles from a selected 290 π^--N (pion-nucleon) collisions have been identified by blob-density and multiple scattering measurements. It is found that the pion often persists in these π^--N collisions, the average persistence is estimated to be 0·24 per collision. It is estimated that π-N and π-π collisions account for 60% and 28% respectively of the secondary particles. The average number of charged shower particles is <n₈>=2·09 ± 0·12, the average number of created charged particles is <n_c ±>=1·94 ±0·12, the average number of protons with energy greater than 300 MeV is <n _p>=0·15 ± 0·05 and the average number of charged kaons is found to be <n_k±>=0·11 ± 0·06. The integral energy spectra of pions in C-system as well as in L-system are well represented by exponential forms. The average inelasticity of the proton in C-system is found to be 0·52 ± 0·10. The charge retention probability for protons in π^--p collisions is 0·45 ± 0·07.