Elastic Scattering of Negative Pions by Protons at 152 and 226 MeV

Abstract

The differential elastic and total cross sections for the scattering of 152- and 226-MeV negative pions by protons have been measured with a liquid hydrogen target and scintillation counters. Analyses of the incident pion beams with a Čerenkov counter yielded higher electron contents than those deduced from range curves. Elastically scattered pions were distinguished from electrons among the scattered particles by use of a Čerenkov counter, or by demanding a coincidence between the scattered pion and recoil proton. The total cross sections measured were 63.7±2.0 and 52.9±1.4 mb at 152 and 226 MeV, respectively. With the present uncertainties, the real parts of the forward scattering amplitudes agree with the predictions of pion dispersion relations.