Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

The transverse spin correlations Ax,x and Ay,y have been measured in the ~d~p ! pspec{pp}sπ−reaction at COSY-ANKE at 353 MeV per nucleon. Here {pp}s denotes a proton-proton pair with low excitation energy, which is dominantly in the 1S0 state. By measuring three protons in the final state it was possible to extract events where there was a spectator proton pspec so that the reaction could be interpreted in terms of quasi-free ~n ~p ! {pp}sπ−. The proton analyzing power in this reaction was also deduced from this data set by averaging over the polarization of the deuteron beam. The values of A^p _y were shown to be consistent with a refined analysis of our earlier results obtained with a polarized proton incident on a deuterium target. Taking these data in combination with our earlier measurements of the differential cross sections and analyzing powers in the ~pp ! {pp}s π0 reaction, a more robust partial wave decomposition was achieved. Three different acceptable solutions were found and the only way of resolving this ambiguity without further theoretical input would be through a measurement of the mixed spin-correlation parameter Ax,z.