The electric charge of interacting cosmic ray particles at sea level

Abstract

The magnitude of the electric charge of sea level cosmic ray particles producing energy transfers greater than or approximately equal to 25 GeV in a 22.9 cm thick steel target have been measured. The charge distribution shows a peak at the electron charge and an apparent high charge tail. Spurious effects contributing to the high charge tail are knock-on electrons, and nuclear interactions in the proportional counter walls, which are used to measure the charge. The limit obtained on the flux of 4e/3, 5e/3 and 7e/3 quarks is less than 8.2*10^-10 cm^-2s^-1sr^-1.