XXII. The large-angle scattering ofμ-mesons in iron

Abstract

The large-angle scattering of μ-mesons in iron has been investigated by a method similar to that reported previously for lead. The measured large-angle distributions are compared with the theories of Molière, Olbert and a modification of Olbert's theory which is based on a single scattering cross section inferred from recent electron-scattering measurements. At energies from several hundred Mev to about 4 Bev the measured distribution, at large angles, is not consistent with present Coulomb scattering theories in which the effects of the finite nuclear dimensions are included. As in the lead experiment, the number of large angles observed is in rough agreement with Moliere's theory for a ‘point’ nucleus. Some properties of the so-called anomalous scattering, which follow from the lead and iron experiments, are discussed.