Inelastic Proton-Proton Collisions at 6.2 Bev

Abstract

Inelastic, 6.2-Bev proton-proton collisions in nuclear emulsions are examined using the internal beam of the Berkeley Bevatron. Multiple scattering, grain density, range, and angle measurements yield the momentum spectra and angular distributions of secondary pions and protons together with the cross sections for accessible final states. The results indicate a cross section of 7.3\ifmmode\pm\else\textpm\fi{}4.6 mb for two prong events, 12.1\ifmmode\pm\else\textpm\fi{}2.4 mb for four prong events, 2.7\ifmmode\pm\else\textpm\fi{}0.6 mb for six prong events, 0.3\ifmmode\pm\else\textpm\fi{}0.3 mb for eight prong events, and 0.2\ifmmode\pm\else\textpm\fi{}0.2 mb for ten prong events, giving a total inelastic cross section of 22.6\ifmmode\pm\else\textpm\fi{}5.3 mb. The average charged pion multiplicity was found to be 1.9\ifmmode\pm\else\textpm\fi{}0.3 and the value of $K$, the average degree of inelasticity, 0.49\ifmmode\pm\else\textpm\fi{}0.05. Comparison of observed partial inelastic cross sections with the predictions of the Fermi statistical theory indicates that this theory underestimates the relative probability for states with high meson multiplicity. Considerable forward and backward peaking was observed in the center-of-mass system angular distributions for secondary protons and, to a lesser extent, for secondary charged pions. Center-of-mass system momentum distributions for secondary charged pions peak at lower momenta than predicted by the statistical theory, while those for protons peak somewhat higher than predicted. Effects are discussed which could account for these discrepancies.