Two-nucleon processes in a coupled-channel approach to pion-nucleus single-charge-exchange reactions

Journal Article · Sun Feb 01 04:00:00 EST 1981 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.23.814· OSTI ID:6665735

Liu, L C

A momentum space coupled-channel formalism is proposed for the study of pion-nucleus single-charge-exchange reactions at medium energies. Formal elimination of certain reaction channels leads to a reduced set of coupled equations with a complex and energy-dependent interaction. A nonperturbative method based upon unitarity considerations is then used to construct each order of this effective pion-nucleus interaction. Our analysis thus leads to a second-order pion-nucleus interaction with analytical properties very different from those obtained from multiple-scattering theory. The theory is applied to the study of pion-/sup 13/C elastic scattering and the single-charge-exchange reaction /sup 13/C(..pi../sup +/,..pi../sup 0/)/sup 13/N(g.s.). Included in our calculations are the first- and second-order pion-nucleus strong interactions, and the pion-nucleus Coulomb interaction. We have calculated the first-order interaction using a covariant, nonstatic theory and have evaluated contributions to the second-order interaction arising from two-nucleon processes related to true pion absorption and to the scattering of pions from a nucleon pair. We present a general relation connecting the second-order pion-nucleus strong interaction potentials of nuclei whose structure do not differ appreciably. Theoretical results for ..pi../sup 13/C elastic scattering predicted by our theory are found to be in good agreement with the data. The calculated excitation function of the single-charge-exchange reaction exhibits a high sensitivity to the type of two-nucleon processes considered. Pion-nucleus single-charge-exchange reactions therefore have promise as a tool for investigating pion-nucleus reaction mechanisms.

• Research Organization: Los Alamos Scientific Laboratory, University of California, Los Alamos, New Mexico 87545
• OSTI ID: 6665735
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 23:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651315* -- Nuclear Properties & Reactions
A=6-19
Theoretical-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON-BARYON INTERACTIONS
CARBON 13 TARGET
CHARGE-EXCHANGE REACTIONS
CHARGED-PARTICLE REACTIONS
COULOMB FIELD
COUPLED CHANNEL THEORY
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELASTIC SCATTERING
ELECTRIC FIELDS
ENERGY LEVELS
ENERGY RANGE
EXCITATION FUNCTIONS
FUNCTIONS
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
INTERACTIONS
ISOBARIC ANALOGS
ISOSPIN
MANY-BODY PROBLEM
MESON REACTIONS
MEV RANGE
MEV RANGE 10-100
MEV RANGE 100-1000
NUCLEAR REACTIONS
NUCLEON-NUCLEON INTERACTIONS
OPTICAL MODELS
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PION PLUS REACTIONS
PION REACTIONS
SCATTERING
SYMMETRY BREAKING
TARGETS
TWO-BODY PROBLEM