Phase shifts and polarization in proton-alpha scattering from 0.9 to 3.2 MeV

Abstract

The measurements of the left-right asymmetry in proton-alpha scattering, described in the preceding paper, are analysed to determine the polarization of the proton beam and to find the phase shifts that best reproduce the polarization and cross section for proton energies below 3.2 MeV. The phase shifts agree with the earlier ones of Critchfield and Dodder, but the new measurements allow a much more accurate determination of the p-wave splitting. The p-wave phase shifts that best fit the experimental data are determined for various assumed values of the s-phase. The effect of d-waves is also investigated. Systematic searches for other sets of phases yield only the previously known four sets, if cross section data alone are used, and four sets, if polarization data alone are used. Only one set satisfies both cross section and polarization data. The polarization calculated from the new phase shits is presented as a contour map.