Wolfenstein polarization observables for the reactions rvec PP → rvec Pπ + N and rvec PP → rvec PPπ0 at 800 MeV and 650 MeV

The first measurements of the Wolfenstein polarization parameters DN,N, DSΩ, and DLΩ, the induced polarization parameter P and analyzing power A for the reactions rvec PP → rvec Pπ + N and rvec PP → rvec PPπ0 at 800 MeV and 650 MeV are reported. The experiment was carried out in the external proton beam area of the Clinton P. Anderson Meson Physics Facility (LAMPF), Los Alamos National Laboratory. The 800Mev and 650Mev polarized proton beam was directed onto a liquid-hydrogen target. Three proton beam polarization directions were used: longitudinal (L), sideways (S) in the scattering plane, and normal (N) to the scattering plane. Scattered protons were analyzed in momentum in the dipole-magnet spectrometer. Two orthogonal polarization components of scattered protons were detected with the polarimeter located directly behind the dipole magnet. The measurements were made with spectrometer spectrometer-polarimeter placed at three central angles, 8.1 degree, 15.2 degree, and 22.0 degree, and the conjugate charged particle detectors covered the regions of 20 degree to 50 degree, and 90 degree to 140 degree, corresponding geometrically to Δ production from ∼5 degree to ∼50 degree in the center-of-mass system. Comparisons are made to results from the model of Dubach, Kloet, and Silbar