Nuclear Interactions in Carbon Produced by Cosmic Rays with Energies between1010and1012ev

Abstract

An experiment is described in which high-energy nuclear interactions in the range of energies 10 10 -10 12 ev were analyzed by means of a cloud chamber in a magnetic field. Measurements of ionization and momentum made possible the identification of electrons and w mesons to about 20 Bev/c. Protons, K mesons, and hyperons could not be identified unambiguously among themselves, except in very limited regions of momentum. The primary particles were cosmic-ray nucleons and a possible fraction of pions, the target nuclei were carbon and the velocities of the primaries were determined from balance of momentum in the centerof-mass system. A total of 41 events were analyzed, and the results compared to previous experimental work and the predictions of the theories of Heisenberg and Landau. The measurements made included the transverse momenta of the secondaries and their average energy in the center-of-mass system, the energy and angular distributions of the pions and heavy particles (protons, K mesons, hyperons) in the center-of-mass system, the inelasticity of the collision, the multiplicity of the showers, the percentage of strange particles, and the positive excess of the secondaries.

Systematic Investigation of Ultrahigh-Energy Interactions. I

“…First, the mean transverse momentum of the shower particles produced, mostly mesons, is about (0.3-0.4) GeV/c and depends on neither the primary energy nor the emission angle, except presumbaly in the extreme forward and/or backward directions. [1][2][3][4][5][6][7][8][9] This is verified also in the machineenergy range where the transverse momenta of the various kinds of particles were accurately measured individually. [10][11][12][13][14][15][16] Second, the inelasticity, i.e., the fraction of incident energy carried away by secondary particles, was estimated in the energy region up to 10 TeV, while in the still higher-energy region, estimation from air-shower experiments is less direct.…”