Polarization phenomena in a dynamical model of NN → NNπ

First calculations for spin-dependent observables of the reactions $p\stackrel{\ensuremath{\rightarrow}}{p}\mathrm{pp}{\ensuremath{\pi}}^{0},$ $p\stackrel{\ensuremath{\rightarrow}}{p}\mathrm{pn}{\ensuremath{\pi}}^{+},$ and $p\stackrel{\ensuremath{\rightarrow}}{p}d{\ensuremath{\pi}}^{+}$ near threshold are presented, employing the J\"ulich model for pion production. The influence of resonant [via the excitation of the $\ensuremath{\Delta}(1232)]$ and nonresonant p-wave pion production mechanisms on these observables is examined. For the reactions $p\stackrel{\ensuremath{\rightarrow}}{p}\mathrm{pn}{\ensuremath{\pi}}^{+}$ and $p\stackrel{\ensuremath{\rightarrow}}{p}d{\ensuremath{\pi}}^{+}$ nice agreement of our predictions with the presently available data on spin correlation coefficents is observed whereas for $p\stackrel{\ensuremath{\rightarrow}}{p}\mathrm{pp}{\ensuremath{\pi}}^{0}$ the description of the data is less satisfying.