T H E PROPERTIES OF PROTON-PROTON I N T E R A C T I O N S BETWEEN 1 O0 AND 1000 GeV FROM A COSMIC-RAY EXPERIMENT *

Proton-proton interactions above 100 GeV have been studied in an experiment using cosmic-ray protons interacting in a liquid hydrogen target. From several hundred hydrogen interactions, it has been learned that: (a) the total inelastic pp cross section is not changing significantly with energy above 30 GeV; (b) the multiplicity distributions of charged prongs agree with a Poisson distribution in charged-particle pairs; (c) the average charged prong multiplicity increases as in s; (d) the angular distribution of charged particles agrees with a c.m. momentum distribution of charged particles that varies as exp exp [ 8 p ~ 8 x 2] d3p/E (where x = PL/Po) and a nucleon distribution that varies as 10x exp [ 3 p~] d3p/E for 0.05 < x < 0.85. Further properties of the angular distributions, characteristics of the ionization calorimeter, the cross section in iron, and other features of the data are reported. * Supported by the U S National Science Foundation. ** Now at Raytheon Corporation, Waltham, Massachusetts. *** Now at Tata Institute for Fundamental Research, Bombay, India. $ Now at Eastern Michigan University, Ypsilanti, Michigan. ~ Now at Augsburg College, St.Paul, Minnesota. 478 L.W. Jones et al., Cosmic-ray experiment