One-nucleon knockout by pions and deltas

Journal Article · Tue Nov 01 04:00:00 EST 1988 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.38.2230· OSTI ID:6739722

Takaki, T; Thies, M

We present the first quantitative study of the (..pi..,..pi..'N) coincidence reaction within the ..delta..-hole model and compare our results to recent Swiss Institute for Nuclear Research (SIN) and LAMPF data for /sup 16/O near 240 MeV. A modified distorted-wave impulse approximation (DWIA), including medium corrections to the ..delta.. propagator and containing no free parameters, reproduces the leading (..pi../sup +/,..pi../sup +/p) channel for p-shell knockout satisfactorily, provided we use shell-model spectroscopic factors. The weak (..pi../sup -/,..pi../sup -/p) and (..pi../sup +/,..pi../sup 0/p) channels are found to be sensitive to interference effects between the DWIA mechanism and knockout induced by ..delta..N collisions. This latter two-step process is also calculated microscopically, using a simple form for the ..delta..-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%.

• Research Organization: Center for Theoretical Physics, Laboratory for Nuclear Science Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 6739722
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 38:5; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYONS
BOSONS
CHARGED-PARTICLE REACTIONS
DELTA BARYONS
DELTA-1232 BARYONS
DIRECT REACTIONS
DISTORTED WAVE THEORY
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
HADRON REACTIONS
HADRONS
IMPULSE APPROXIMATION
INELASTIC SCATTERING
ISOSPIN
KNOCK-OUT REACTIONS
MATHEMATICAL MODELS
MESON REACTIONS
MESONS
MEV RANGE
MEV RANGE 100-1000
N BARYONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEONS
OXYGEN 16 TARGET
PARTICLE PROPERTIES
PION REACTIONS
PIONS
PSEUDOSCALAR MESONS
RESONANCE SCATTERING
SCATTERING
SHELL MODELS
TARGETS