Abstract
We present the first quantitative study of the (π,π’N) coincidence reaction within the Δ-hole model and compare our results to recent Swiss Institute for Nuclear Research (SIN) and LAMPF data for near 240 MeV. A modified distorted-wave impulse approximation (DWIA), including medium corrections to the Δ propagator and containing no free parameters, reproduces the leading (,p) channel for p-shell knockout satisfactorily, provided we use shell-model spectroscopic factors. The weak (,p) and (,p) channels are found to be sensitive to interference effects between the DWIA mechanism and knockout induced by ΔN collisions. This latter two-step process is also calculated microscopically, using a simple form for the Δ-N interaction guided by pion absorption. Our model qualitatively confirms earlier estimates, but cannot reproduce the isospin ratios over the whole kinematical range. In particular, it systematically underestimates the charge-exchange cross sections by 30%.
- Received 18 April 1988
DOI:https://doi.org/10.1103/PhysRevC.38.2230
©1988 American Physical Society