Off-shell form factors and low energy theorems for pion photoproduction

Journal Article · Fri Jun 01 00:00:00 EDT 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.41.2852· OSTI ID:6938866

Naus, H W.L. ^[1]; Koch, J H ^[2]; Friar, J L ^[3]

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1. National Institute for Nuclear Physics and High Energy Physics, Section K (NIKHEF-K), P.O. Box 41882, NL-1009 DB Amsterdam, (The Netherlands)
2. National Institute for Nuclear Physics and High Energy Physics (NIKHEF-K) and Institute for Theoretical Physics, University of Amsterdam, Amsterdam, (The Netherlands)
3. Theory Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA)

The derivation of the low energy theorem for threshold photoproduction of neutral pions on a nucleon is reconsidered. Instead of considering explicitly the Born terms, as done in earlier derivations, a more general class of diagrams is separated from the total amplitude. Gauge invariance is imposed on the operator level and the partial conservation of the axial-vector current constraint is incorporated. Besides recovering the older results in this approach, relations for the off-shell behavior of the strong and electromagnetic vertices are derived.

• OSTI ID: 6938866
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Vol. 41:6; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
PIONS NEUTRAL
PHOTOPRODUCTION
ELECTROMAGNETIC FORM FACTORS
GAUGE INVARIANCE
PCAC THEORY
PION-NUCLEON INTERACTIONS
BASIC INTERACTIONS
BOSONS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FORM FACTORS
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
INVARIANCE PRINCIPLES
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PIONS
PSEUDOSCALAR MESONS
653003* - Nuclear Theory- Nuclear Reactions & Scattering