The Mesotron Momentum Spectrum at 4.35-km Altitude

Abstract

The mesotron momentum spectrum has been determined at Mount Evans, Colorado, from the shape of the absorption curve in lead as measured by Geiger-Müller counter telescopes. Special attention was paid to eliminating the contribution of single electrons to the measured intensity. A large number of low energy mesotrons were found, resulting in a sharp maximum of the momentum spectrum lying between 1 and 2×${10}^8$ ev/c. A simple power law is not adequate to describe the spectrum in the entire region investigated.