Pion production in dp -> dN pi reactions with deuteron projectiles - art. no. 064002

Kinematically complete events have been studied for the reactions dp-->dp p i (0) and dp-->dn pi (+) at projectile energies between 437 and 559 MeV. Th e measurement covers a range of pion momenta eta =p(pi ,c.m.)(max)/m(pi)c f rom near the production threshold (eta =0.32) to eta =0.86 close to the NN- ->NN pi threshold. The measurements were performed at the CELSIUS storage r ing with the PROMICE/WASA setup. Angular and spectral distributions of the charged ejectiles as well as total cross sections are decomposed into the f ractions that can be attributed to a quasifree NN-->d pi process with a spe ctator nucleon, and to a process involving all three nucleons. The quasifre e contribution increases with energy and dominates from the NN-->NN pi thre shold on. The results are compared to calculations with a spectator model w ith and without dp final state interactions.