Organizational procedure for the study of pion production and absorption processes on nuclei

Journal Article · Tue Feb 01 04:00:00 EST 1983 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.27.657· OSTI ID:6258788

Banerjee, M K; Walker, G E

For nuclear processes involving pions, such as pion production/absorption or exchange currents, it is shown that a natural organization involves adoption of the ..pi..NN vertex function g/sub ..pi../(q/sup 2/)..gamma../sub 5/tau/sub ..cap alpha../, where q is the pion four-momentum and g/sub ..pi../(m/sub ..pi../ /sup 2/)approx. =13.4 is the renormalized pion-nucleon coupling constant. The result is independent of the form and details of any fundamental interaction Lagrangian. The difference between g/sub ..pi../(q/sup 2/)..gamma../sub 5/tau/sub ..cap alpha../ and the fully-dressed ..pi..NN vertex function contributes to amplitudes involving more bosons, e.g., scattering amplitudes (..pi..N..--> pi..N), production amplitudes (..pi..N..--> pi pi..N), etc. Such contributions are mediated through either seagull-like terms or P11 intermediate states. It is pointed out that it is neither necessary nor practical to calculate these partial contributions to scattering and production amplitudes. One can always exploit other approaches, theoretical and phenomenological, to make reasonably good models for the full amplitudes. The usual procedure of including the effects of negative energy parts of the nucleon propagator in interaction potentials, exchange currents, etc., is easily included in the present organization. The result is that from scattering amplitudes, etc; the positive energy nucleon poles are deleted but Z graphs are included.

• Research Organization: Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742
• OSTI ID: 6258788
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 27:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
BOSONS
CHARGED-PARTICLE REACTIONS
COUPLING CONSTANTS
ELEMENTARY PARTICLES
FUNCTIONS
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
MESON REACTIONS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
NUCLEAR REACTIONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PION REACTIONS
PION-NUCLEON INTERACTIONS
PIONS
PROPAGATOR
PSEUDOSCALAR MESONS
SCATTERING AMPLITUDES
SPACE-TIME
VERTEX FUNCTIONS