Neutral pion production by 17 GeV negative pions in carbon

Abstract

Nentral pion production by 17 GeV/c negative pions incident on carbon nuclei has been studied. It is found that a great majority of the neutral pions is produced isotropically in the barycentric system of the incident pion and a target pion at rest in the laboratory system. The energy spectrum of the neutral pions in the laboratory system is much steeper than the corresponding spectrum obtained in proton collisions. It is shown that energetic pions from the decay of the forward nucleon isobar produced in proton collisions may account for most of this difference. Elastic charge exchange probability per collision is found to be less than 1/530. Average transverse momentum of neutral pions is found to be (220 ±10) MeV, which is significantly smaller than the corresponding value for charged pions as determined in bubble chamber experiments.