Dependence of {rvec {ital p}}{rvec {ital p}} {r_arrow} {ital pp{pi}}thinsp{sup 0} near 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}{sub T}thinsp/{sigma}{sub tot} for {rvec p}{rvec p}{r_arrow} pp{pi}{sup 0} , as well as the polar integrals of the spin correlation coefficient combination A{sub xx}{minus}A{sub yy} , and the analyzing power A{sub y} at four bombarding energies between 325 and 400thinspthinspMeV. 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. {copyright} {ital 1998} {ital The American Physical Society }