Effects of bound-state approximations on distorted-wave Born approximation and multistep processes in the channel-coupling-array theory

Journal Article · Mon Aug 01 04:00:00 EDT 1977 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.16.556· OSTI ID:7288506

Kouri, D J; Levin, F S

The effects of approximating the equations of the channel-coupling-array theory by retaining only bound internal states of the clusters in two-body channels are studied. This approximation corresponds to those used in standard direct nuclear reaction calculations. By use of Lippmann's identity, the exact channel-coupling-array equations may be written in two alternate forms (different off-shell extensions) which respond differently to the bound-state approximation. When the bound state approximation is made on the equations in ''folded'' form, its main effect is that the distorted-wave Born approximation occurs in only one of the two-body channels, a modified distorted-wave Born approximation occurs in another, and no first order amplitudes of any kind occur in the remaining channels. If Lippmann's identity is first used to unfold the exact channel-coupling-array equations (thereby yielding a different off-shell extension) and then the bound state approximation is applied, distorted-wave Born approximation amplitudes are found in all channels. The need for accurate, nonperturbative solutions to the approximate equations so as to assess the effects of possible low-order approximations is stressed.

• Research Organization: Departments of Chemistry and Physics, University of Houston, Houston, Texas 77004
• OSTI ID: 7288506
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 16:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BORN APPROXIMATION
BOUND STATE
CLUSTER MODEL
COUPLED CHANNEL THEORY
DWBA
FUNCTIONS
GREEN FUNCTION
HAMILTONIANS
MANY-BODY PROBLEM
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
MATRIX ELEMENTS
NUCLEAR MODELS
PERTURBATION THEORY
QUANTUM OPERATORS
SHELL MODELS
TWO-BODY PROBLEM