Abstract
Kinematically complete events have been studied for the reactions and at projectile energies between 437 and 559 MeV. The measurement covers a range of pion momenta from near the production threshold to close to the threshold. The measurements were performed at the CELSIUS storage ring with the PROMICE/WASA setup. Angular and spectral distributions of the charged ejectiles as well as total cross sections are decomposed into the fractions that can be attributed to a quasifree process with a spectator nucleon, and to a process involving all three nucleons. The quasifree contribution increases with energy and dominates from the threshold on. The results are compared to calculations with a spectator model with and without final state interactions.
- Received 16 June 2000
DOI:https://doi.org/10.1103/PhysRevC.62.064002
©2000 American Physical Society