Scattering of Negative Pions by Hydrogen

Abstract

The scattering of negative pions by liquid hydrogen has been studied with the 450-Mev synchrocyclotron, using the pion beams of energy 169 Mev, 194 Mev, and 210 Mev. Angular distributions for ordinary scattering and for photon production are presented for each of the three primary energies. The differential cross sections for ordinary scattering and for charge-exchange scattering are computed for the center-of-mass system. The charge-exchange cross sections when plotted as a function of the energy appear to go through a maximum at about 180 Mev. On the other hand, the ordinary scattering cross sections appear to increase steadily with the energy. The charge exchange cross sections, which at lower energies are predominantly backward, become rapidly forward as the energy increases, and are strongly forward at the highest energy.