Short - range NN - properties in the processes pd → dp and pd → ( pp ) n

The data from the first measurement, performed at ANKE/COSY, of the unpolarized cross section of the reaction pd → (pp)n in the kinematics of backward elastic pd → dp scattering at protonbeam energies between 0.6 and 1.9 GeV are analyzed in a phenomenological approach. The pd → (pp)n data and the triplet cross section of the reaction pd → (pn)p, calculated from the pd → dp data on the basis of the Fäldt-Wilkin extrapolation, are used here to derive the ratio ζ of the singlet production matrix element squared to the triplet one. This ratio, defined in our earlier analysis of pd → (pn)p data in a largely model-independent way, depends on the dynamics of the pd interaction. We find here ζ ≈ 0.02 and show that the smallness of this value may point toward softness of the deuteron at short NN distances. PACS. 13.75.Cs Nucleon-nucleon interactions (including antinucleons, deuterons, etc.) – 25.10.+s Nuclear reactions involving few-nucleon systems