The NN final-state interaction in the helicity structure of d→(γ→,π−)pp reaction

The influence of final-state NN-rescattering on the helicity structure of the γ→d→→π−pp reaction in the energy range from π-threshold up to 550 MeV has been investigated. The differential polarized cross-section difference for the parallel and antiparallel helicity states is predicted and compared with recent experimental data. It is shown that the effect of NN-rescattering is much less important in the polarized differential cross-section difference than in the previously studied unpolarized differential cross section. Furthermore, the contribution of γ→d→→π−pp to the spin asymmetry of the deuteron is explicitly evaluated over the region of the Δ(1232)-resonance with inclusion of NN-rescattering. The effect of NN final-state interaction is found to be much larger in the asymmetry than in the total cross section and leads to an appreciable reduction of the spin asymmetry in the Δ-region.