PionProton ChargeExchange Scattering from 500 to 1300 MeV
Abstract
Differential cross sections for the reaction π^{}p>π^{0}n were measured at nine incidentpion kinetic energies in the interval from 500 to 1300 MeV. The negative pion beam from the bevatron was focused on a liquidhydrogen target completely surrounded by a cubic array of six steelplate spark chambers. The spark chambers were triggered on events with neutral final states. Chargeexchange events were identified from the oneshower and twoshower events in the sparkchamber pictures. By the Monte Carlo technique, the π^{0} distributions were calculated from the bisector distributions of the twoshower π^{0} events together with the observed γray distributions of the oneshower π^{0} events. These π^{0} distributions were fitted with both Legendrepolynomial expansions and powerseries expansions by the method of least squares. The extrapolated forward differential cross sections are in good agreement with the dispersion calculations. The Legendre coefficients for the differential cross sections in isospin state T=12 were obtained by combining our results with available data on π^{+/}p elastic scattering. In the light of existing phaseshift solutions, the behavior of these coefficients is discussed. The D_{5}F_{5} interference term that peaks near 900 MeV is verified to be in isospin state T=12 only. We report here also the total neutral cross sections and the cross sections for the production of neutral multipion final states 2π^{0}n and 3π^{0}n. The 4π solid angle and the calibrated energy response of the spark chambers contribute to the accuracy of the results.
 Publication:

Physical Review
 Pub Date:
 April 1967
 DOI:
 10.1103/PhysRev.156.1415
 Bibcode:
 1967PhRv..156.1415C