An estimation of the primary proton spectrum between 1012and 1014eV

Abstract

Based on measurements of the unaccompanied charged hadron flux from 10¹¹ to 10¹⁴ eV at mountain altitudes, the authors estimate the primary proton flux using recently determined proton-proton total cross sections from new measurements of the real part of the forward scattering amplitude at ISR, and Glauber theory to calculate the proton-air inelastic cross section. The derived spectrum agrees well with extrapolation of the direct measurements below 2*10¹² eV without change of slope.