Multi-pion production in the dd→αX reaction

A simple model, based on two parallel and independent NN→dπ processes, has recently been proposed for two-pion production in the dd→αX reaction. It reproduces all observed features, including the sharp peak structure in momentum distributions (the ABC effect) and the strong oscillations in the deuteron vector and tensor analyzing powers. This model is now extended to describe also four-pion production with the same basic mechanism, but with two np→dππ processes as input. The calculations of the high missing mass spectra are in fair agreement with the experimental data for beam energies in the range 1.9