Impulse approximation versus elementary particle method: Pion photoproduction and radiative muon capture

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.29.223· OSTI ID:5169952

Klieb, L; Rood, H P.C.

General differences between the impulse approximation and the elementary particle method in the treatment of two-step processes like pion photoproduction and radiative muon and pion capture are discussed. Important numerical differences arise, exemplified by pion photoproduction on /sup 3/He. The reason is that the Born approximation with low-energy theorems leaves terms undetermined in the elementary particle method. In particular it is shown that in pion photoproduction in pseudo- p scalar coupling the impulse approximation accounts for numerically sizable contributions of intermediate nuclear excited states not contained in the elementary particle method. In pseudovector coupling no unique and unambiguous relation between the pion-nucleus coupling constant and pion photoproduction holds. An earlier calculation of radiative muon capture by /sup 3/He is improved by including in a semiempirical way exchange contributions to the muon radiating diagram.

• Research Organization: Institute for Theoretical Physics, State University of Groningen, Groningen, The Netherlands
• OSTI ID: 5169952
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 29:1; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651215* -- Nuclear Properties & Reactions
A=1-5
Theoretical-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BASIC INTERACTIONS
BORN APPROXIMATION
BOSONS
CAPTURE
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
COUPLING CONSTANTS
CROSS SECTIONS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FERMIONS
GAMMA SPECTRA
HADRONS
HELIUM 3 TARGET
IMPULSE APPROXIMATION
INTERACTIONS
LEPTON REACTIONS
LEPTONS
MASSLESS PARTICLES
MESONS
MUON REACTIONS
MUONS
MUONS MINUS
NUCLEAR REACTIONS
PARTICLE PRODUCTION
PHOTONS
PHOTONUCLEAR REACTIONS
PHOTOPRODUCTION
PIONS
PIONS PLUS
PSEUDOSCALAR MESONS
SPECTRA
TARGETS
TRITONS