  A model for the d d -> alpha pi pi reaction, based on two parallel N N -> d
pi reactions, is extended to incorporate a complete set of input amplitudes.
While low-energy cross sections are underestimated, the rich structure observed
in the alpha-particle momentum distributions for 0.8 < T_d < 1.9 GeV (the ABC
effect) is extraordinarily well reproduced. In addition, a recent measurement
of deuteron analyzing powers agrees quite well with our predictions, both in
frequency and magnitude of the oscillations.
