Dependence ofp→p→→ppπ0near Threshold on the Spin of the Colliding Nucleons

A polarized internal atomic-hydrogen target and a stored, polarized beam are used to measure the spin-dependent total cross section $\Delta {\sigma }_T/{\sigma }_{\mathrm{tot}}$ for $\overrightarrow{p}\overrightarrow{p}\to \mathrm{pp}{\pi }^0$, as well as the polar integrals of the spin correlation coefficient combination $A_{\mathrm{xx}}{-A}_{\mathrm{yy}}$, and the analyzing power $A_y$ at four bombarding energies between 325 and 400 MeV. This experiment is made possible by the use of a cooled beam in a storage ring. The polarization observables are used to study the contribution from individual partial waves.