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.
@article{arxiv.nucl-th/9812004,
title = {Structure in two_pion production in the d d -> alpha X reaction},
author = {Anders Gardestig and Goran Faldt and Colin Wilkin},
journal= {arXiv preprint arXiv:nucl-th/9812004},
year = {2009}
}